Immunological origins of binding and catalysis in a Diels-Alderase antibody.
Romesberg, F.E., Spiller, B., Schultz, P.G., Stevens, R.C.(1998) Science 279: 1929-1933
- PubMed: 9506942
- DOI: https://doi.org/10.1126/science.279.5358.1929
- Primary Citation of Related Structures:
1A4J, 1A4K - PubMed Abstract:
The three-dimensional structure of an antibody (39-A11) that catalyzes a Diels-Alder reaction has been determined. The structure suggests that the antibody catalyzes this pericyclic reaction through a combination of packing and hydrogen-bonding interactions that control the relative geometries of the bound substrates and electronic distribution in the dienophile. A single somatic mutation, serine-91 of the light chain to valine, is largely responsible for the increase in affinity and catalytic activity of the affinity-matured antibody. Structural and functional studies of the germ-line precursor suggest that 39-A11 and related antibodies derive from a family of germ-line genes that have been selected throughout evolution for the ability of the encoded proteins to form a polyspecific combining site. Germ line-encoded antibodies of this type, which can rapidly evolve into high-affinity receptors for a broad range of structures, may help to expand the binding potential associated with the structural diversity of the primary antibody repertoire.
Organizational Affiliation:
Howard Hughes Medical Institute and the Department of Chemistry, University of California, Berkeley, CA 94720, USA. 94720, USA.