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.
Submitter: Stephanie Contreras
Submission Date: Dec. 15, 2020, 3:44 p.m.
|Structure ID||Release Date||Resolution||Structure Title|
|1BOG||1998-08-04T00:00:00+0000||2.6||ANTI-P24 (HIV-1) FAB FRAGMENT CB41 COMPLEXED WITH AN EPITOPE-HOMOLOGOUS PEPTIDE|
|1CFN||1999-03-19T00:00:00+0000||2.65||ANTI-P24 (HIV-1) FAB FRAGMENT CB41 COMPLEXED WITH AN EPITOPE-RELATED PEPTIDE|
|1CFQ||1999-03-19T00:00:00+0000||2.8||ANTI-P24 (HIV-1) FAB FRAGMENT CB41|
|1CFS||1999-03-19T00:00:00+0000||2.75||ANTI-P24 (HIV-1) FAB FRAGMENT CB41 COMPLEXED WITH AN EPITOPE-UNRELATED PEPTIDE|
|1CFT||1999-03-19T00:00:00+0000||2.8||ANTI-P24 (HIV-1) FAB FRAGMENT CB41 COMPLEXED WITH AN EPITOPE-UNRELATED D-PEPTIDE|
|1FRG||1994-01-17T00:00:00+0000||2.8||CRYSTAL STRUCTURE, SEQUENCE, AND EPITOPE MAPPING OF A PEPTIDE COMPLEX OF AN ANTI-INFLUENZA HA PEPTIDE ANTIBODY FAB 26(SLASH)9: FINE-TUNING ANTIBODY SPECIFICITY|
|1HH6||2000-12-21T00:00:00+0000||2.6||ANTI-P24 (HIV-1) FAB FRAGMENT CB41 COMPLEXED WITH A PEPTIDE|
|1HH9||2000-12-21T00:00:00+0000||2.7||ANTI-P24 (HIV-1) FAB FRAGMENT CB41 COMPLEXED WITH A PEPTIDE|
|1HI6||2001-01-02T00:00:00+0000||2.55||ANTI-P24 (HIV-1) FAB FRAGMENT CB41 COMPLEXED WITH A PEPTIDE|
|1BFV||1997-05-27T00:00:00+0000||2.1||MONOCLONAL ANTIBODY FRAGMENT FV4155 FROM E. COLI|