title: Antibody evolution constrains conformational heterogeneity by tailoring protein dynamics.
abstract: The evolution of proteins with novel function is thought to start from precursor proteins that are conformationally heterogeneous. The corresponding genes may be duplicated and then mutated to select and optimize a specific conformation. However, testing this idea has been difficult because of the challenge of quantifying protein flexibility and conformational heterogeneity as a function of evolution. Here, we report the characterization of protein heterogeneity and dynamics as a function of evolution for the antifluorescein antibody 4-4-20. Using nonlinear laser spectroscopy, surface plasmon resonance, and molecular dynamics simulations, we demonstrate that evolution localized the Ab-combining site from a heterogeneous ensemble of conformations to a single conformation by introducing mutations that act cooperatively and over significant distances to rigidify the protein. This study demonstrates how protein dynamics may be tailored by evolution and has important implications for our understanding of how novel protein functions are evolved.
authors.affiliation: Department of Chemistry, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA 92037, USA.
authors.forename: Jörg
authors.initials: J
authors.lastname: Zimmermann
authors.forename: Erin L
authors.initials: EL
authors.lastname: Oakman
authors.forename: Ian F
authors.initials: IF
authors.lastname: Thorpe
authors.forename: Xinghua
authors.initials: X
authors.lastname: Shi
authors.forename: Paul
authors.initials: P
authors.lastname: Abbyad
authors.forename: Charles L
authors.initials: CL
authors.lastname: Brooks
authors.forename: Steven G
authors.initials: SG
authors.lastname: Boxer
authors.forename: Floyd E
authors.initials: FE
authors.lastname: Romesberg
mesh_terms: D000818:Animals; D000906:Antibodies / Q000737:chemistry* / Q000235:genetics; D019143:Evolution, Molecular; D019793:Fluorescein; D006801:Humans; D007140:Immunoglobulin Fab Fragments / Q000737:chemistry* / Q000235:genetics; D009154:Mutation; D011487:Protein Conformation; D011506:Proteins / Q000737:chemistry* / Q000235:genetics; D020349:Surface Plasmon Resonance
chemical_list: D000906:Antibodies; D007140:Immunoglobulin Fab Fragments; D011506:Proteins; D019793:Fluorescein