@article{Huang2024b,

title = {Designed endocytosis-inducing proteins degrade targets and amplify signals},

author = {Buwei Huang and Mohamad Abedi and Green Ahn and Brian Coventry and Isaac Sappington and Cong Tang and Rong Wang and Thomas Schlichthaerle and Jason Z. Zhang and Yujia Wang and Inna Goreshnik and Ching Wen Chiu and Adam Chazin-Gray and Sidney Chan and Stacey Gerben and Analisa Murray and Shunzhi Wang and Jason O’Neill and Li Yi and Ronald Yeh and Ayesha Misquith and Anitra Wolf and Luke M. Tomasovic and Dan I. Piraner and Maria J. Duran Gonzalez and Nathaniel R. Bennett and Preetham Venkatesh and Maggie Ahlrichs and Craig Dobbins and Wei Yang and Xinru Wang and Danny D. Sahtoe and Dionne Vafeados and Rubul Mout and Shirin Shivaei and Longxing Cao and Lauren Carter and Lance Stewart and Jamie B. Spangler and Kole T. Roybal and Per Jr Greisen and Xiaochun Li and Gonçalo J. L. Bernardes and Carolyn R. Bertozzi and David Baker},

url = {https://www.nature.com/articles/s41586-024-07948-2, Nature [Open Access] },

doi = {10.1038/s41586-024-07948-2},

year  = {2024},

date = {2024-09-25},

urldate = {2024-09-25},

journal = {Nature},

publisher = {Springer Science and Business Media LLC},

abstract = {Endocytosis and lysosomal trafficking of cell surface receptors can be triggered by endogenous ligands. Therapeutic approaches such as lysosome-targeting chimaeras1,2 (LYTACs) and cytokine receptor-targeting chimeras3 (KineTACs) have used this to target specific proteins for degradation by fusing modified native ligands to target binding proteins. Although powerful, these approaches can be limited by competition with native ligands and requirements for chemical modification that limit genetic encodability and can complicate manufacturing, and, more generally, there may be no native ligands that stimulate endocytosis through a given receptor. Here we describe computational design approaches for endocytosis-triggering binding proteins (EndoTags) that overcome these challenges. We present EndoTags for insulin-like growth factor 2 receptor (IGF2R) and asialoglycoprotein receptor (ASGPR), sortilin and transferrin receptors, and show that fusing these tags to soluble or transmembrane target protein binders leads to lysosomal trafficking and target degradation. As these receptors have different tissue distributions, the different EndoTags could enable targeting of degradation to different tissues. EndoTag fusion to a PD-L1 antibody considerably increases efficacy in a mouse tumour model compared to antibody alone. The modularity and genetic encodability of EndoTags enables AND gate control for higher-specificity targeted degradation, and the localized secretion of degraders from engineered cells. By promoting endocytosis, EndoTag fusion increases signalling through an engineered ligand–receptor system by nearly 100-fold. EndoTags have considerable therapeutic potential as targeted degradation inducers, signalling activators for endocytosis-dependent pathways, and cellular uptake inducers for targeted antibody–drug and antibody–RNA conjugates.



},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Humphreys2024,

title = {Protein interactions in human pathogens revealed through deep learning},

author = {Ian R. Humphreys and Jing Zhang and Minkyung Baek and Yaxi Wang and Aditya Krishnakumar and Jimin Pei and Ivan Anishchenko and Catherine A. Tower and Blake A. Jackson and Thulasi Warrier and Deborah T. Hung and S. Brook Peterson and Joseph D. Mougous and Qian Cong and David Baker},

url = {https://www.nature.com/articles/s41564-024-01791-x, Nature Microbiology [Open Access]},

doi = {10.1038/s41564-024-01791-x},

issn = {2058-5276},

year  = {2024},

date = {2024-09-18},

urldate = {2024-09-18},

journal = {Nature Microbiology},

publisher = {Springer Science and Business Media LLC},

abstract = {Identification of bacterial protein–protein interactions and predicting the structures of these complexes could aid in the understanding of pathogenicity mechanisms and developing treatments for infectious diseases. Here we developed RoseTTAFold2-Lite, a rapid deep learning model that leverages residue–residue coevolution and protein structure prediction to systematically identify and structurally characterize protein–protein interactions at the proteome-wide scale. Using this pipeline, we searched through 78 million pairs of proteins across 19 human bacterial pathogens and identified 1,923 confidently predicted complexes involving essential genes and 256 involving virulence factors. Many of these complexes were not previously known; we experimentally tested 12 such predictions, and half of them were validated. The predicted interactions span core metabolic and virulence pathways ranging from post-transcriptional modification to acid neutralization to outer-membrane machinery and should contribute to our understanding of the biology of these important pathogens and the design of drugs to combat them.



},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Berhanu2024,

title = {Sculpting conducting nanopore size and shape through de novo protein design},

author = {Samuel Berhanu and Sagardip Majumder and Thomas Müntener and James Whitehouse and Carolin Berner and Asim K. Bera and Alex Kang and Binyong Liang and Nasir Khan and Banumathi Sankaran and Lukas K. Tamm and David J. Brockwell and Sebastian Hiller and Sheena E. Radford and David Baker and Anastassia A. Vorobieva},

url = {https://www.science.org/doi/10.1126/science.adn3796, Science},

doi = {10.1126/science.adn3796},

year  = {2024},

date = {2024-07-19},

urldate = {2024-07-19},

journal = {Science},

publisher = {American Association for the Advancement of Science (AAAS)},

abstract = {Transmembrane β-barrels have considerable potential for a broad range of sensing applications. Current engineering approaches for nanopore sensors are limited to naturally occurring channels, which provide suboptimal starting points. By contrast, de novo protein design can in principle create an unlimited number of new nanopores with any desired properties. Here we describe a general approach to designing transmembrane β-barrel pores with different diameters and pore geometries. Nuclear magnetic resonance and crystallographic characterization show that the designs are stably folded with structures resembling those of the design models. The designs have distinct conductances that correlate with their pore diameter, ranging from 110 picosiemens (~0.5 nanometer pore diameter) to 430 picosiemens (~1.1 nanometer pore diameter). Our approach opens the door to the custom design of transmembrane nanopores for sensing and sequencing applications.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Peruzzi2024b,

title = {Enhancing extracellular vesicle cargo loading and functional delivery by engineering protein-lipid interactions},

author = {Justin A. Peruzzi and Taylor F. Gunnels and Hailey I. Edelstein and Peilong Lu and David Baker and Joshua N. Leonard and Neha P. Kamat},

url = {https://www.nature.com/articles/s41467-024-49678-z [Nature Communications, Open Access]},

doi = {10.1038/s41467-024-49678-z},

year  = {2024},

date = {2024-07-04},

urldate = {2024-12-00},

journal = {Nature Communications},

publisher = {Springer Science and Business Media LLC},

abstract = {Naturally generated lipid nanoparticles termed extracellular vesicles (EVs) hold significant promise as engineerable therapeutic delivery vehicles. However, active loading of protein cargo into EVs in a manner that is useful for delivery remains a challenge. Here, we demonstrate that by rationally designing proteins to traffic to the plasma membrane and associate with lipid rafts, we can enhance loading of protein cargo into EVs for a set of structurally diverse transmembrane and peripheral membrane proteins. We then demonstrate the capacity of select lipid tags to mediate increased EV loading and functional delivery of an engineered transcription factor to modulate gene expression in target cells. We envision that this technology could be leveraged to develop new EV-based therapeutics that deliver a wide array of macromolecular cargo.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Goverde2024,

title = {Computational design of soluble and functional membrane protein analogues},

author = {Casper A. Goverde and Martin Pacesa and Nicolas Goldbach and Lars J. Dornfeld and Petra E. M. Balbi and Sandrine Georgeon and Stéphane Rosset and Srajan Kapoor and Jagrity Choudhury and Justas Dauparas and Christian Schellhaas and Simon Kozlov and David Baker and Sergey Ovchinnikov and Alex J. Vecchio and Bruno E. Correia},

url = {https://www.nature.com/articles/s41586-024-07601-y, Nature [Open Access]

},

doi = {10.1038/s41586-024-07601-y},

issn = {1476-4687},

year  = {2024},

date = {2024-06-19},

urldate = {2024-06-19},

journal = {Nature},

publisher = {Springer Science and Business Media LLC},

abstract = {De novo design of complex protein folds using solely computational means remains a substantial challenge. Here we use a robust deep learning pipeline to design complex folds and soluble analogues of integral membrane proteins. Unique membrane topologies, such as those from G-protein-coupled receptors, are not found in the soluble proteome, and we demonstrate that their structural features can be recapitulated in solution. Biophysical analyses demonstrate the high thermal stability of the designs, and experimental structures show remarkable design accuracy. The soluble analogues were functionalized with native structural motifs, as a proof of concept for bringing membrane protein functions to the soluble proteome, potentially enabling new approaches in drug discovery. In summary, we have designed complex protein topologies and enriched them with functionalities from membrane proteins, with high experimental success rates, leading to a de facto expansion of the functional soluble fold space.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Craven2024,

title = {Computational Design of Cyclic Peptide Inhibitors of a Bacterial Membrane Lipoprotein Peptidase},

author = {Timothy W. Craven and Mark D. Nolan and Jonathan Bailey and Samir Olatunji and Samantha J. Bann and Katherine Bowen and Nikita Ostrovitsa and Thaina M. Da Costa and Ross D. Ballantine and Dietmar Weichert and Paul M. Levine and Lance J. Stewart and Gaurav Bhardwaj and Joan A. Geoghegan and Stephen A. Cochrane and Eoin M. Scanlan and Martin Caffrey and David Baker},

url = {https://pubs.acs.org/doi/10.1021/acschembio.4c00076, ACS Chem. Bio. [Open Access]

https://www.bakerlab.org/wp-content/uploads/2024/05/craven-et-al-2024-computational-design-of-cyclic-peptide-inhibitors-of-a-bacterial-membrane-lipoprotein-peptidase.pdf, PDF},

doi = {10.1021/acschembio.4c00076},

year  = {2024},

date = {2024-05-07},

urldate = {2024-05-07},

journal = {ACS Chemical Biology},

publisher = {American Chemical Society (ACS)},

abstract = {There remains a critical need for new antibiotics against multi-drug-resistant Gram-negative bacteria, a major global threat that continues to impact mortality rates. Lipoprotein signal peptidase II is an essential enzyme in the lipoprotein biosynthetic pathway of Gram-negative bacteria, making it an attractive target for antibacterial drug discovery. Although natural inhibitors of LspA have been identified, such as the cyclic depsipeptide globomycin, poor stability and production difficulties limit their use in a clinical setting. We harness computational design to generate stable de novo cyclic peptide analogues of globomycin. Only 12 peptides needed to be synthesized and tested to yield potent inhibitors, avoiding costly preparation of large libraries and screening campaigns. The most potent analogues showed comparable or better antimicrobial activity than globomycin in microdilution assays against ESKAPE-E pathogens. This work highlights computational design as a general strategy to combat antibiotic resistance.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{An2023,

title = {Hallucination of closed repeat proteins containing central pockets},

author = {An L, Hicks DR, Zorine D, Dauparas J, Wicky BIM, Milles LF, Courbet A, Bera AK, Nguyen H, Kang A, Carter L, Baker D},

url = {https://www.nature.com/articles/s41594-023-01112-6, Nature Structural & Molecular Biology [Open Access] },

doi = {10.1038/s41594-023-01112-6},

year  = {2023},

date = {2023-09-28},

urldate = {2023-09-28},

journal = {Nature Structural & Molecular Biology},

abstract = {In pseudocyclic proteins, such as TIM barrels, β barrels, and some helical transmembrane channels, a single subunit is repeated in a cyclic pattern, giving rise to a central cavity that can serve as a pocket for ligand binding or enzymatic activity. Inspired by these proteins, we devised a deep-learning-based approach to broadly exploring the space of closed repeat proteins starting from only a specification of the repeat number and length. Biophysical data for 38 structurally diverse pseudocyclic designs produced in Escherichia coli are consistent with the design models, and the three crystal structures we were able to obtain are very close to the designed structures. Docking studies suggest the diversity of folds and central pockets provide effective starting points for designing small-molecule binders and enzymes.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Goldbach2023,

title = {De novo design of monomeric helical bundles for pH-controlled membrane lysis},

author = {Nicolas Goldbach and Issa Benna and Basile I. M. Wicky and Jacob T. Croft and Lauren Carter and Asim K. Bera and Hannah Nguyen and Alex Kang and Banumathi Sankaran and Erin C. Yang and Kelly K. Lee and David Baker},

url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/pro.4769, Protein Science

https://www.bakerlab.org/wp-content/uploads/2023/08/Protein-Science-2023-Goldbach.pdf, PDF},

doi = {https://doi.org/10.1002/pro.4769},

year  = {2023},

date = {2023-08-26},

urldate = {2023-08-26},

journal = {Protein Science},

abstract = {Targeted intracellular delivery via receptor-mediated endocytosis requires the delivered cargo to escape the endosome to prevent lysosomal degradation. This can in principle be achieved by membrane lysis tightly restricted to endosomal membranes upon internalization to avoid general membrane insertion and lysis. Here we describe the design of small monomeric proteins with buried histidine containing pH-responsive hydrogen bond networks and membrane permeating amphipathic helices. Of 30 designs that were experimentally tested, all expressed in E. coli, 13 were monomeric with the expected secondary structure, and 4 designs disrupted artificial liposomes in a pH-dependent manner. Mutational analysis showed that the buried histidine hydrogen bond networks mediate pH-responsiveness and control lysis of model membranes within a very narrow range of pH (6.0 - 5.5) with almost no lysis occurring at neutral pH. These tightly controlled lytic monomers could help mediate endosomal escape in designed targeted delivery platforms.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Wang2023,

title = {Improving the secretion of designed protein assemblies through negative design of cryptic transmembrane domains},

author = {Wang, Jing Yang (John)

and Khmelinskaia, Alena

and Sheffler, William

and Miranda, Marcos C.

and Antanasijevic, Aleksandar

and Borst, Andrew J.

and Torres, Susana V.

and Shu, Chelsea

and Hsia, Yang

and Nattermann, Una

and Ellis, Daniel

and Walkey, Carl

and Ahlrichs, Maggie

and Chan, Sidney

and Kang, Alex

and Nguyen, Hannah

and Sydeman, Claire

and Sankaran, Banumathi

and Wu, Mengyu

and Bera, Asim K.

and Carter, Lauren

and Fiala, Brooke

and Murphy, Michael

and Baker, David

and Ward, Andrew B.

and King, Neil P.},

url = {https://www.pnas.org/doi/10.1073/pnas.2214556120, PNAS (Open Access)},

doi = {10.1073/pnas.2214556120},

year  = {2023},

date = {2023-03-08},

urldate = {2023-03-08},

journal = {Proceedings of the National Academy of Sciences},

abstract = {Computationally designed protein nanoparticles have recently emerged as a promising platform for the development of new vaccines and biologics. For many applications, secretion of designed nanoparticles from eukaryotic cells would be advantageous, but in practice, they often secrete poorly. Here we show that designed hydrophobic interfaces that drive nanoparticle assembly are often predicted to form cryptic transmembrane domains, suggesting that interaction with the membrane insertion machinery could limit efficient secretion. We develop a general computational protocol, the Degreaser, to design away cryptic transmembrane domains without sacrificing protein stability. The retroactive application of the Degreaser to previously designed nanoparticle components and nanoparticles considerably improves secretion, and modular integration of the Degreaser into design pipelines results in new nanoparticles that secrete as robustly as naturally occurring protein assemblies. Both the Degreaser protocol and the nanoparticles we describe may be broadly useful in biotechnological applications.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Bhardwaj2022,

title = {Accurate de novo design of membrane-traversing macrocycles},

author = {Gaurav Bhardwaj and Jacob O’Connor and Stephen Rettie and Yen-Hua Huang and Theresa A. Ramelot and Vikram Khipple Mulligan and Gizem Gokce Alpkilic and Jonathan Palmer and Asim K. Bera and Matthew J. Bick and Maddalena {Di Piazza} and Xinting Li and Parisa Hosseinzadeh and Timothy W. Craven and Roberto Tejero and Anna Lauko and Ryan Choi and Calina Glynn and Linlin Dong and Robert Griffin and Wesley C. {van Voorhis} and Jose Rodriguez and Lance Stewart and Gaetano T. Montelione and David Craik and David Baker},

url = {https://www.sciencedirect.com/science/article/pii/S0092867422009229?via%3Dihub, Cell

https://www.bakerlab.org/wp-content/uploads/2022/08/1-s2.0-S0092867422009229-main.pdf, PDF},

doi = {10.1016/j.cell.2022.07.019},

year  = {2022},

date = {2022-08-29},

urldate = {2022-08-29},

journal = {Cell},

abstract = {We use computational design coupled with experimental characterization to systematically investigate the design principles for macrocycle membrane permeability and oral bioavailability. We designed 184 6–12 residue macrocycles with a wide range of predicted structures containing noncanonical backbone modifications and experimentally determined structures of 35; 29 are very close to the computational models. With such control, we show that membrane permeability can be systematically achieved by ensuring all amide (NH) groups are engaged in internal hydrogen bonding interactions. 84 designs over the 6–12 residue size range cross membranes with an apparent permeability greater than 1 × 10−6 cm/s. Designs with exposed NH groups can be made membrane permeable through the design of an alternative isoenergetic fully hydrogen-bonded state favored in the lipid membrane. The ability to robustly design membrane-permeable and orally bioavailable peptides with high structural accuracy should contribute to the next generation of designed macrocycle therapeutics.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Macé2022,

title = {Cryo-EM structure of a type IV secretion system},

author = {Macé, Kévin

and Vadakkepat, Abhinav K.

and Redzej, Adam

and Lukoyanova, Natalya

and Oomen, Clasien

and Braun, Nathalie

and Ukleja, Marta

and Lu, Fang

and Costa, Tiago R. D.

and Orlova, Elena V.

and Baker, David

and Cong, Qian

and Waksman, Gabriel},

url = {https://www.nature.com/articles/s41586-022-04859-y, Nature

https://www.bakerlab.org/wp-content/uploads/2022/08/Mace2022s41586-022-04859-y.pdf, PDF},

doi = {10.1038/s41586-022-04859-y},

year  = {2022},

date = {2022-07-01},

urldate = {2022-07-01},

journal = {Nature},

abstract = {Bacterial conjugation is the fundamental process of unidirectional transfer of DNAs, often plasmid DNAs, from a donor cell to a recipient cell1. It is the primary means by which antibiotic resistance genes spread among bacterial populations2,3. In Gram-negative bacteria, conjugation is mediated by a large transport apparatus—the conjugative type IV secretion system (T4SS)—produced by the donor cell and embedded in both its outer and inner membranes. The T4SS also elaborates a long extracellular filament—the conjugative pilus—that is essential for DNA transfer4,5. Here we present a high-resolution cryo-electron microscopy (cryo-EM) structure of a 2.8 megadalton T4SS complex composed of 92 polypeptides representing 8 of the 10 essential T4SS components involved in pilus biogenesis. We added the two remaining components to the structural model using co-evolution analysis of protein interfaces, to enable the reconstitution of the entire system including the pilus. This structure describes the exceptionally large protein–protein interaction network required to assemble the many components that constitute a T4SS and provides insights on the unique mechanism by which they elaborate pili.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Vorobieva2021,

title = {De novo design of transmembrane beta barrels},

author = {Vorobieva, Anastassia A. and White, Paul and Liang, Binyong and Horne, Jim E. and Bera, Asim K. and Chow, Cameron M. and Gerben, Stacey and Marx, Sinduja and Kang, Alex and Stiving, Alyssa Q. and Harvey, Sophie R. and Marx, Dagan C. and Khan, G. Nasir and Fleming, Karen G. and Wysocki, Vicki H. and Brockwell, David J. and Tamm, Lukas K. and Radford, Sheena E. and Baker, David},

url = {https://science.sciencemag.org/content/371/6531/eabc8182, Science

https://www.bakerlab.org/wp-content/uploads/2021/02/Vorobieva_etal_Science2021_De_Novo_Transmembrane_beta_barrels.pdf, Download PDF},

doi = {10.1126/science.abc8182},

year  = {2021},

date = {2021-02-19},

urldate = {2021-02-19},

journal = {Science},

volume = {371},

number = {6531},

abstract = {Computational design offers the possibility of making proteins with customized structures and functions. The range of accessible protein scaffolds has expanded with the design of increasingly complex cytoplasmic proteins and, recently, helical membrane proteins. Vorobieva et al. describe the successful computational design of eight-stranded transmembrane β-barrel proteins (TMBs). Using an iterative approach, they show the importance of negative design to prevent off-target structures and gain insight into the sequence determinants of TMB folding. Twenty-three designs satisfied biochemical screens for a TMB structure, and two structures were experimentally validated by nuclear magnetic resonance spectroscopy or x-ray crystallography. This is a step toward the custom design of pores for applications such as single-molecule sequencing.Science, this issue p. eabc8182INTRODUCTIONDespite their key biological roles, only a few proteins that fold into lipid membranes have been designed de novo. A class of membrane proteins{textemdash}transmembrane β barrels (TMBs){textemdash}forms a continuous sheet that closes on itself in lipid membranes. In addition to the challenge of designing β-sheet proteins, which are prone to misfolding and aggregation if folding is not properly controlled, the computational design of TMBs is complicated by limited understanding of TMB folding. As a result, no TMB has been designed de novo to date.Although the folding of TMBs in vivo is catalyzed by the β-barrel assembly machinery (BAM), many TMBs can also fold spontaneously in synthetic membranes to form stable pores, making them attractive for biotechnology and single-molecule analytical applications. Hence, de novo design of TMBs has potential both for understanding the determinants of TMB folding and membrane insertion and for the custom engineering of TMB nanopores.RATIONALEWe used de novo protein design to distill key principles of TMB folding through several design-build-test cycles. We iterated between hypothesis formulation, its implementation into computational design methods, and experimental characterization of the resulting proteins. To focus on the fundamental principles of TMB folding in the absence of complications due to interactions with chaperones and BAM in vivo, we focused on the challenge of de novo design of eight-stranded TMBs, which can fold and assemble into synthetic lipid membranes.RESULTSWe used a combination of purely geometric models and explicit Rosetta protein structure simulations to determine the constraints that β-strand connectivity and membrane embedding place on the TMB architecture. Through a series of design-build-test cycles, we found that, unlike almost all other classes of proteins, locally destabilizing sequences are critical for expression and folding of TMBs, and that the β-turns that translocate through the bilayer during folding have to be destabilized to enable correct assembly in the membrane. Our results suggest that premature formation of β hairpins may result in off-target β-sheet structures that compete with proper membrane insertion and folding, and hence the β hairpins of TMBs must be designed such that they are only transiently formed prior to membrane insertion, when the protein is in an aqueous environment. In the hydrophobic environment of the lipid bilayer, the full TMB can assemble because the membrane-facing nonpolar residues, which would tend to cluster nonspecifically in an aqueous environment, instead make favorable interactions with the lipids. As the TMB assembles, the β hairpins are stabilized by interactions with the neighboring β strands.Using computational methods that incorporate the above insights, we designed TMB sequences that successfully fold and assemble into both detergent micelles and lipid bilayers. Two of the designs were highly stable and could fold into liposomes more rapidly and reversibly than the transmembrane domain of the model outer membrane protein A (tOmpA) of Escherichia coli. A nuclear magnetic resonance solution structure and a high-resolution crystal structure for two different designs closely match the design models, showing that the TMB design method developed here can generate new structures with atomic-level accuracy.CONCLUSIONThis study elucidates key principles for de novo design of transmembrane β barrels, ranging from constraints on β-barrel architecture and β-hairpin design, as well as local and global sequence features. Our designs provide starting points for the bottom-up elucidation of the molecular mechanisms underlying TMB folding and interactions with the cellular outer membrane folding and insertion machinery. More generally, our work demonstrates that TMBs can be designed with atomic-level accuracy and opens the door to custom design of nanopores tailored for applications such as single-molecule sensing and sequencing.De novo{textendash}designed eight-stranded transmembrane β barrels fold spontaneously and reversibly into synthetic lipid membranes.The illustration shows the crystal structure of the protein TMB2.17 designed in this study, which adopts a structure identical to the design model.Credit: Ian Haydon.Transmembrane β-barrel proteins (TMBs) are of great interest for single-molecule analytical technologies because they can spontaneously fold and insert into membranes and form stable pores, but the range of pore properties that can be achieved by repurposing natural TMBs is limited. We leverage the power of de novo computational design coupled with a {textquotedblleft}hypothesis, design, and test{textquotedblright} approach to determine TMB design principles, notably, the importance of negative design to slow β-sheet assembly. We design new eight-stranded TMBs, with no homology to known TMBs, that insert and fold reversibly into synthetic lipid membranes and have nuclear magnetic resonance and x-ray crystal structures very similar to the computational models. These advances should enable the custom design of pores for a wide range of applications.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Ben-Sasson2020,

title = {Design of biologically active binary protein 2D materials},

author = {Ben-Sasson, Ariel J. and Watson, Joseph L. and Sheffler, William and Johnson, Matthew Camp and Bittleston, Alice and Somasundaram, Logeshwaran and Decarreau, Justin and Jiao, Fang and Chen, Jiajun and Mela, Ioanna and Drabek, Andrew A. and Jarrett, Sanchez M. and Blacklow, Stephen C. and Kaminski, Clemens F. and Hura, Greg L. and De Yoreo, James J. and Kollman, Justin M. and Ruohola-Baker, Hannele and Derivery, Emmanuel and Baker, David},

url = {https://www.nature.com/articles/s41586-020-03120-8, Nature

https://www.bakerlab.org/wp-content/uploads/2021/02/Ben-Sasson_Nature2021_Binary_2D_arrays.pdf, Download PDF},

doi = {10.1038/s41586-020-03120-8},

year  = {2021},

date = {2021-01-06},

urldate = {2021-01-06},

journal = {Nature},

abstract = {Ordered two-dimensional arrays such as S-layers1,2 and designed analogues3–5 have intrigued bioengineers6,7, but with the exception of a single lattice formed with flexible linkers8, they are constituted from just one protein component. Materials composed of two components have considerable potential advantages for modulating assembly dynamics and incorporating more complex functionality9–12. Here we describe a computational method to generate co-assembling binary layers by designing rigid interfaces between pairs of dihedral protein building blocks, and use it to design a p6m lattice. The designed array components are soluble at millimolar concentrations, but when combined at nanomolar concentrations, they rapidly assemble into nearly crystalline micrometre-scale arrays nearly identical to the computational design model in vitro and in cells without the need for a two-dimensional support. Because the material is designed from the ground up, the components can be readily functionalized and their symmetry reconfigured, enabling formation of ligand arrays with distinguishable surfaces, which we demonstrate can drive extensive receptor clustering, downstream protein recruitment and signalling. Using atomic force microscopy on supported bilayers and quantitative microscopy on living cells, we show that arrays assembled on membranes have component stoichiometry and structure similar to arrays formed in vitro, and that our material can therefore impose order onto fundamentally disordered substrates such as cell membranes. In contrast to previously characterized cell surface receptor binding assemblies such as antibodies and nanocages, which are rapidly endocytosed, we find that large arrays assembled at the cell surface suppress endocytosis in a tunable manner, with potential therapeutic relevance for extending receptor engagement and immune evasion. Our work provides a foundation for a synthetic cell biology in which multi-protein macroscale materials are designed to modulate cell responses and reshape synthetic and living systems.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Xu2020,

title = {Computational design of transmembrane pores},

author = {Chunfu Xu and Peilong Lu and Tamer M. Gamal El-Din and Xue Y. Pei and Matthew C. Johnson and Atsuko Uyeda and Matthew J. Bick and Qi Xu and Daohua Jiang and Hua Bai and Gabriella Reggiano and Yang Hsia and T J Brunette and Jiayi Dou and Dan Ma and Eric M. Lynch and Scott E. Boyken and Po-Ssu Huang and Lance Stewart and Frank DiMaio and Justin M. Kollman and Ben F. Luisi and Tomoaki Matsuura and William A. Catterall and David Baker },

url = {https://www.bakerlab.org/wp-content/uploads/2020/08/Xuetal_Nature2020_DeNovoPores.pdf

https://www.nature.com/articles/s41586-020-2646-5},

doi = {10.1038/s41586-020-2646-5},

year  = {2020},

date = {2020-08-26},

journal = {Nature},

volume = {585},

pages = {129–134},

abstract = {Transmembrane channels and pores have key roles in fundamental biological processes and in biotechnological applications such as DNA nanopore sequencing, resulting in considerable interest in the design of pore-containing proteins. Synthetic amphiphilic peptides have been found to form ion channels, and there have been recent advances in de novo membrane protein design and in redesigning naturally occurring channel-containing proteins. However, the de novo design of stable, well-defined transmembrane protein pores that are capable of conducting ions selectively or are large enough to enable the passage of small-molecule fluorophores remains an outstanding challenge. Here we report the computational design of protein pores formed by two concentric rings of α-helices that are stable and monodisperse in both their water-soluble and their transmembrane forms. Crystal structures of the water-soluble forms of a 12-helical pore and a 16-helical pore closely match the computational design models. Patch-clamp electrophysiology experiments show that, when expressed in insect cells, the transmembrane form of the 12-helix pore enables the passage of ions across the membrane with high selectivity for potassium over sodium; ion passage is blocked by specific chemical modification at the pore entrance. When incorporated into liposomes using in vitro protein synthesis, the transmembrane form of the 16-helix pore—but not the 12-helix pore—enables the passage of biotinylated Alexa Fluor 488. A cryo-electron microscopy structure of the 16-helix transmembrane pore closely matches the design model. The ability to produce structurally and functionally well-defined transmembrane pores opens the door to the creation of designer channels and pores for a wide variety of applications.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Boyken2019,

title = {De novo design of tunable, pH-driven conformational changes},

author = {Boyken, Scott E. and Benhaim, Mark A. and Busch, Florian and Jia, Mengxuan and Bick, Matthew J. and Choi, Heejun and Klima, Jason C. and Chen, Zibo and Walkey, Carl and Mileant, Alexander and Sahasrabuddhe, Aniruddha and Wei, Kathy Y. and Hodge, Edgar A. and Byron, Sarah and Quijano-Rubio, Alfredo and Sankaran, Banumathi and King, Neil P. and Lippincott-Schwartz, Jennifer and Wysocki, Vicki H. and Lee, Kelly K. and Baker, David

},

url = {https://science.sciencemag.org/content/364/6441/658

https://www.bakerlab.org/wp-content/uploads/2019/06/Boyken_etal2019_pH_conformational_changes.pdf},

doi = {10.1126/science.aav7897},

year  = {2019},

date = {2019-05-17},

journal = {Science},

volume = {364},

number = {6441},

pages = {658-664},

abstract = {The ability of naturally occurring proteins to change conformation in response to environmental changes is critical to biological function. Although there have been advances in the de novo design of stable proteins with a single, deep free-energy minimum, the design of conformational switches remains challenging. We present a general strategy to design pH-responsive protein conformational changes by precisely preorganizing histidine residues in buried hydrogen-bond networks. We design homotrimers and heterodimers that are stable above pH 6.5 but undergo cooperative, large-scale conformational changes when the pH is lowered and electrostatic and steric repulsion builds up as the network histidine residues become protonated. The transition pH and cooperativity can be controlled through the number of histidine-containing networks and the strength of the surrounding hydrophobic interactions. Upon disassembly, the designed proteins disrupt lipid membranes both in vitro and after being endocytosed in mammalian cells. Our results demonstrate that environmentally triggered conformational changes can now be programmed by de novo protein design.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Lu1042,

title = {Accurate computational design of multipass transmembrane proteins},

author = {Lu, Peilong and Min, Duyoung and DiMaio, Frank and Wei, Kathy Y. and Vahey, Michael D. and Boyken, Scott E. and Chen, Zibo and Fallas, Jorge A. and Ueda, George and Sheffler, William and Mulligan, Vikram Khipple and Xu, Wenqing and Bowie, James U. and Baker, David},

url = {http://science.sciencemag.org/content/359/6379/1042

https://www.bakerlab.org/wp-content/uploads/2018/03/Lu_Science_2018.pdf},

doi = {10.1126/science.aaq1739},

issn = {0036-8075},

year  = {2018},

date = {2018-03-02},

journal = {Science},

volume = {359},

number = {6379},

pages = {1042--1046},

abstract = {In recent years, soluble protein design has achieved successes such as artificial enzymes and large protein cages. Membrane proteins present a considerable design challenge, but here too there have been advances, including the design of a zinc-transporting tetramer. Lu et al. report the design of stable transmembrane monomers, homodimers, trimers, and tetramers with up to eight membrane-spanning regions in an oligomer. The designed proteins adopted the target oligomerization state and localized to the predicted cellular membranes, and crystal structures of the designed dimer and tetramer reflected the design models.Science, this issue p. 1042The computational design of transmembrane proteins with more than one membrane-spanning region remains a major challenge. We report the design of transmembrane monomers, homodimers, trimers, and tetramers with 76 to 215 residue subunits containing two to four membrane-spanning regions and up to 860 total residues that adopt the target oligomerization state in detergent solution. The designed proteins localize to the plasma membrane in bacteria and in mammalian cells, and magnetic tweezer unfolding experiments in the membrane indicate that they are very stable. Crystal structures of the designed dimer and tetramer{textemdash}a rocket-shaped structure with a wide cytoplasmic base that funnels into eight transmembrane helices{textemdash}are very close to the design models. Our results pave the way for the design of multispan membrane proteins with new functions.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Ovchinnikov294,

title = {Protein structure determination using metagenome sequence data},

author = { Sergey Ovchinnikov and Hahnbeom Park and Neha Varghese and Po-Ssu Huang and Georgios A. Pavlopoulos and David E. Kim and Hetunandan Kamisetty and Nikos C. Kyrpides and David Baker},

url = {https://www.bakerlab.org/wp-content/uploads/2017/01/ovchinnikov_science_2017.pdf

http://science.sciencemag.org/content/355/6322/294},

doi = {10.1126/science.aah4043},

issn = {0036-8075},

year  = {2017},

date = {2017-01-01},

journal = {Science},

volume = {355},

number = {6322},

pages = {294--298},

publisher = {American Association for the Advancement of Science},

abstract = {Fewer than a third of the 14,849 known protein families have at least one member with an experimentally determined structure. This leaves more than 5000 protein families with no structural information. Protein modeling using residue-residue contacts inferred from evolutionary data has been successful in modeling unknown structures, but it requires large numbers of aligned sequences. Ovchinnikov et al. augmented such sequence alignments with metagenome sequence data (see the Perspective by S"oding). They determined the number of sequences required to allow modeling, developed criteria for model quality, and, where possible, improved modeling by matching predicted contacts to known structures. Their method predicted quality structural models for 614 protein families, of which about 140 represent newly discovered protein folds.Science, this issue p. 294; see also p. 248Despite decades of work by structural biologists, there are still ~5200 protein families with unknown structure outside the range of comparative modeling. We show that Rosetta structure prediction guided by residue-residue contacts inferred from evolutionary information can accurately model proteins that belong to large families and that metagenome sequence data more than triple the number of protein families with sufficient sequences for accurate modeling. We then integrate metagenome data, contact-based structure matching, and Rosetta structure calculations to generate models for 614 protein families with currently unknown structures; 206 are membrane proteins and 137 have folds not represented in the Protein Data Bank. This approach provides the representative models for large protein families originally envisioned as the goal of the Protein Structure Initiative at a fraction of the cost.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{626,

title = {Immobilizing affinity proteins to nitrocellulose: a toolbox for paper-based assay developers.},

author = { Carly A Holstein and Aaron Chevalier and Steven Bennett and Caitlin E Anderson and Karen Keniston and Cathryn Olsen and Bing Li and Brian Bales and David R Moore and Elain Fu and David Baker and Paul Yager},

url = {http://www.bakerlab.org/wp-content/uploads/2015/12/Holstien_Anal_Bioanal_Chem_2015.pdf},

doi = {10.1007/s00216-015-9052-0},

issn = {1618-2650},

year  = {2015},

date = {2015-10-01},

journal = {Analytical and bioanalytical chemistry},

abstract = {To enable enhanced paper-based diagnostics with improved detection capabilities, new methods are needed to immobilize affinity reagents to porous substrates, especially for capture molecules other than IgG. To this end, we have developed and characterized three novel methods for immobilizing protein-based affinity reagents to nitrocellulose membranes. We have demonstrated these methods using recombinant affinity proteins for the influenza surface protein hemagglutinin, leveraging the customizability of these recombinant "flu binders" for the design of features for immobilization. The three approaches shown are: (1) covalent attachment of thiolated affinity protein to an epoxide-functionalized nitrocellulose membrane, (2) attachment of biotinylated affinity protein through a nitrocellulose-binding streptavidin anchor protein, and (3) fusion of affinity protein to a novel nitrocellulose-binding anchor protein for direct coupling and immobilization. We also characterized the use of direct adsorption for the flu binders, as a point of comparison and motivation for these novel methods. Finally, we demonstrated that these novel methods can provide improved performance to an influenza hemagglutinin assay, compared to a traditional antibody-based capture system. Taken together, this work advances the toolkit available for the development of next-generation paper-based diagnostics.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{608,

title = {The modular structure of the inner-membrane ring component PrgK facilitates assembly of the type III secretion system basal body},

author = { Julien R C Bergeron and Liam J Worrall and Soumya De and Nikolaos G Sgourakis and Adrienne H Cheung and Emilie Lameignere and Mark Okon and Gregory A Wasney and David Baker and Lawrence P McIntosh and Natalie C J Strynadka},

url = {http://www.bakerlab.org/wp-content/uploads/2015/12/themodularstructure_Baker2015.pdf},

doi = {10.1016/j.str.2014.10.021},

issn = {1878-4186},

year  = {2015},

date = {2015-01-01},

journal = {Structure (London, England : 1993)},

volume = {23},

pages = {161-72},

abstract = {The type III secretion system (T3SS) is a large macromolecular assembly found at the surface of many pathogenic Gram-negative bacteria. Its role is to inject toxic "effector" proteins into the cells of infected organisms. The molecular details of the assembly of this large, multimembrane-spanning complex remain poorly understood. Here, we report structural, biochemical, and functional analyses of PrgK, an inner-membrane component of the prototypical Salmonella typhimurium T3SS. We have obtained the atomic structures of the two ring building globular domains and show that the C-terminal transmembrane helix is not essential for assembly and secretion. We also demonstrate that structural rearrangement of the two PrgK globular domains, driven by an interconnecting linker region, may promote oligomerization into ring structures. Finally, we used electron microscopy-guided symmetry modeling to propose a structural model for the intimately associated PrgH-PrgK ring interaction within the assembled basal body.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{622,

title = {High-resolution modeling of transmembrane helical protein structures from distant homologues.},

author = { Kuang-Yui M Chen and Jiaming Sun and Jason S Salvo and David Baker and Patrick Barth},

url = {http://www.bakerlab.org/wp-content/uploads/2015/12/Chen_PLOS_2014.pdf},

doi = {10.1371/journal.pcbi.1003636},

issn = {1553-7358},

year  = {2014},

date = {2014-05-01},

journal = {PLoS computational biology},

volume = {10},

pages = {e1003636},

abstract = {Eukaryotic transmembrane helical (TMH) proteins perform a wide diversity of critical cellular functions, but remain structurally largely uncharacterized and their high-resolution structure prediction is currently hindered by the lack of close structural homologues. To address this problem, we present a novel and generic method for accurately modeling large TMH protein structures from distant homologues exhibiting distinct loop and TMH conformations. Models of the adenosine A2AR and chemokine CXCR4 receptors were first ranked in GPCR-DOCK blind prediction contests in the receptor structure accuracy category. In a benchmark of 50 TMH protein homolog pairs of diverse topology (from 5 to 12 TMHs), size (from 183 to 420 residues) and sequence identity (from 15% to 70%), the method improves most starting templates, and achieves near-atomic accuracy prediction of membrane-embedded regions. Unlike starting templates, the models are of suitable quality for computer-based protein engineering: redesigned models and redesigned X-ray structures exhibit very similar native interactions. The method should prove useful for the atom-level modeling and design of a large fraction of structurally uncharacterized TMH proteins from a wide range of structural homologues.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}