Directed evolution of antibody fragments with monovalent femtomolar antigen-binding affinity.
Abstract
Single-chain antibody mutants have been evolved in vitro with antigen-binding equilibrium dissociation constant K(d) = 48 fM and slower dissociation kinetics (half-time > 5 days) than those for the streptavidin-biotin complex. These mutants possess the highest monovalent ligand-binding affinity yet reported for an engineered protein by over two orders of magnitude. Optimal kinetic screening of randomly mutagenized libraries of 10(5)-10(7) yeast surface-displayed antibodies enabled a >1,000-fold decrease in the rate of dissociation after four cycles of affinity mutagenesis and screening. The consensus mutations are generally nonconservative by comparison with naturally occurring mouse Fv sequences and with residues that do not contact the fluorescein antigen in the wild-type complex. The existence of these mutants demonstrates that the antibody Fv architecture is not intrinsically responsible for an antigen-binding affinity ceiling during in vivo affinity maturation.
Submission Details
ID: wLTG2sYt
Submitter: Stephanie Contreras
Submission Date: Dec. 15, 2020, 3:44 p.m.
Version: 1
Publication Details
Boder ET;Midelfort KS;Wittrup KD,Proc Natl Acad Sci U S A (2000) Directed evolution of antibody fragments with monovalent femtomolar antigen-binding affinity. PMID:10984501Additional Information
Study Summary
| Number of data points | 39 |
| Proteins | 4-4-20 FAB fragment |
| Unique complexes | 35 |
| Assays/Quantities/Protocols | Experimental Assay: kdiss (x10^-6) |
| Libraries | single chain antibody mutants |
Structure view and single mutant data analysis
Study data
| Colors: | D | E | R | H | K | S | T | N | Q | A | V | I | L | M | F | Y | W | C | G | P |
|---|
Data Distribution
Studies with similar sequences (approximate matches)