1aj7
From Proteopedia
IMMUNOGLOBULIN 48G7 GERMLINE FAB ANTIBODY COMPLEXED WITH HAPTEN 5-(PARA-NITROPHENYL PHOSPHONATE)-PENTANOIC ACID. AFFINITY MATURATION OF AN ESTEROLYTIC ANTIBODY
Overview
The crystal structures of a germline antibody Fab fragment and its complex with hapten have been solved at 2.1 A resolution. These structures are compared with the corresponding crystal structures of the affinity-matured antibody, 48G7, which has a 30,000 times higher affinity for hapten as a result of nine replacement somatic mutations. Significant changes in the configuration of the combining site occur upon binding of hapten to the germline antibody, whereas hapten binds to the mature antibody by a lock-and-key fit mechanism. The reorganization of the combining site that was nucleated by hapten binding is further optimized by somatic mutations that occur up to 15 from bound hapten. These results suggest that the binding potential of the primary antibody repertoire may be significantly expanded by the ability of germline antibodies to adopt more than one combining-site configuration, with both antigen binding and somatic mutation stabilizing the configuration with optimal hapten complementarity.
About this Structure
1AJ7 is a Protein complex structure of sequences from Homo sapiens and Mus musculus. Full crystallographic information is available from OCA.
Reference
Structural insights into the evolution of an antibody combining site., Wedemayer GJ, Patten PA, Wang LH, Schultz PG, Stevens RC, Science. 1997 Jun 13;276(5319):1665-9. PMID:9180069 Page seeded by OCA on Fri May 2 10:20:28 2008
