The design and characterization of two proteins with 88% sequence identity but different structure and function.

ABSTRACT: To identify a simplified code for conformational switching, we have redesigned two natural proteins to have 88% sequence identity but different tertiary structures: a 3-alpha helix fold and an alpha/beta fold. We describe the design of these homologous heteromorphic proteins, their structural properties as determined by NMR, their conformational stabilities, and their affinities for their respective ligands: IgG and serum albumin. Each of these proteins is completely folded at 25 degrees C, is monomeric, and retains the native binding activity. The complete binding epitope for both ligands is encoded within each of the proteins. The IgG-binding epitope is functional only in the alpha/beta fold, and the albumin-binding epitope is functional only in the 3-alpha fold. These results demonstrat

SUBMITTER: Alexander PA 

PROVIDER: S-EPMC1906725 | biostudies-literature | 2007 Jul

REPOSITORIES: biostudies-literature