A phage display system for studying the sequence determinants of protein folding

TitleA phage display system for studying the sequence determinants of protein folding
Publication TypeJournal Article
Year of Publication1995
AuthorsGu, H., Yi Q., Bray S. T., Riddle D. S., Shiau A. K., & Baker D.
JournalProtein science
Volume4
Issue6
Pagination1108-17
Date Published1995 Jun
ISSN0961-8368
KeywordsAmino Acid Sequence, Bacterial Proteins, Bacteriophage M13, Base Sequence, Circular Dichroism, Gene Library, Genetic Vectors, Models, Molecular, Molecular Sequence Data, Mutagenesis, Plasmids, Primary Publication, Protein Denaturation, Protein Folding, Recombinant Proteins, Selection, Genetic, Structure-Activity Relationship
Abstract

We have developed a phage display system that provides a means to select variants of the IgG binding domain of peptostreptococcal protein L that fold from large combinatorial libraries. The premise underlying the selection scheme is that binding of protein L to IgG requires that the protein be properly folded. Using a combination of molecular biological and biophysical methods, we show that this assumption is valid. First, the phage selection procedure strongly selects against a point mutation in protein L that disrupts folding but is not in the IgG binding interface. Second, variants recovered from a library in which the first third of protein L was randomized are properly folded. The degree of sequence variation in the selected population is striking: the variants have as many as nine substitutions in the 14 residues that were mutagenized. The approach provides a selection for "foldedness" that is potentially applicable to any small binding protein.

Alternate JournalProtein Sci.
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