1KEM

CATALYTIC ANTIBODY 28B4 FAB FRAGMENT

Summary for 1KEM

• Entry DOI: 10.2210/pdb1kem/pdb
• Descriptor: 28B4 FAB (2 entities in total)
• Functional Keywords: sulfide oxidation, monooxygenase, oxygenation, fab, immunoglobulin, catalytic antibody
• Biological source: Mus musculus (house mouse); More
• Cellular location: Isoform Secreted: Secreted: P01868
• Total number of polymer chains: 2
• Total formula weight: 47385.83

Authors

Hsieh-Wilson, L.C.,Schultz, P.G.,Stevens, R.C. (deposition date: 1996-04-16, release date: 1996-12-07, Last modification date: 2024-10-09)

Primary citation

Hsieh-Wilson, L.C.,Schultz, P.G.,Stevens, R.C.
Insights into antibody catalysis: structure of an oxygenation catalyst at 1.9-angstrom resolution.
Proc.Natl.Acad.Sci.USA, 93:5363-5367, 1996

PubMed Abstract: The x-ray crystal structures of the sulfide oxidase antibody 28B4 and of antibody 28B4 complexed with hapten have been solved at 2.2-angstrom and 1.9-angstrom resolution, respectively. To our knowledge, these structures are the highest resolution catalytic antibody structures to date and provide insight into the molecular mechanism of this antibody-catalyzed monooxygenation reaction. Specifically, the data suggest that entropic restriction plays a fundamental role in catalysis through the precise alignment of the thioether substrate and oxidant. The antibody active site also stabilizes developing charge on both sulfur and periodate in the transition state via cation-pi and electrostatic interactions, respectively. In addition to demonstrating that the active site of antibody 28B4 does indeed reflect the mechanistic information programmed in the aminophosphonic acid hapten, these high-resolution structures provide a basis for enhancing turnover rates through mutagenesis and improved hapten design.

PubMed: 8643580
DOI: 10.1073/pnas.93.11.5363

Experimental method

X-RAY DIFFRACTION (2.2 Å)