PMID: 12552112 , Related PDB ids: 1N7M, 1NGW, 1NGY, 1NGZ

Authors:

Yin J, Andryski SE, Beuscher AE 4th, Stevens RC, Schultz PG

Title:

Structural evidence for substrate strain in antibody catalysis.

Journal:

Proc Natl Acad Sci U S A. 2003 Feb 4;100(3):856-61. Epub 2003 Jan 24.

Abstract:

The crystal structure of the Michaelis complex between the Fab fragment of ferrochelatase antibody 7G12 and its substrate mesoporphyrin has been solved to 2.6-A resolution. The antibody-bound mesoporphyrin clearly adopts a nonplanar conformation and reveals that the antibody catalyzes the porphyrin metallation reaction by straining/distorting the bound substrate toward the transition-state configuration. The crystal structures of the Fab fragment of the germ-line precursor antibody to 7G12 and its complex with the hapten N-methylmesoporphyrin have also been solved. A comparison of these structures with the corresponding structures of the affinity-matured antibody 7G12 reveals the molecular mechanism by which the immune system evolves binding energy to catalyze this reaction.