title: DNA hydrolysis by monoclonal autoantibody BV 04-01.
abstract: Monoclonal anti-DNA autoantibody BV 04-01 catalyzed hydrolysis of DNA in the presence of Mg2+. Catalysis was associated with BV 04-01 IgG, Fab, and single-chain-antibody (SCA) proteins. Cleavage of both ss and dsDNA was observed with efficient hydrolysis of the C-rich region of A7C7ATATAGCGCGT2, as well as a preference for cleaving within CG-rich regions of dsDNA. Data on specificity of ssDNA hydrolysis and kinetic data obtained from wild-type SCA, and two SCA mutants were used to model the catalytically active antibody site using the previously resolved X-ray structure of BV 04-01. The resulting model suggested that the target phosphodiester bond is activated by induction of conformational strain. In addition, the antibody-DNA complex contained a Mg2+ coordination site composed of the L32Tyr and L27dHis side chains and a DNA 3'-phosphodiester group. Induction of strain along with the metal coordination could be part of the mechanism by which this antibody catalyzes DNA hydrolysis. Sequence data for BV 04-01 V(H) and V(L) genes suggested that the proposed catalytic-antibody active site was germline-encoded. This observation suggests that catalytic activity might represent an important-rarely examined-function for some antibody molecules.
authors.affiliation: Department of Pathology and Laboratory Medicine, University of Texas-Houston, Medical School, 7225-0708, USA.
authors.forename: L S
authors.initials: LS
authors.lastname: Rodkey
authors.forename: G
authors.initials: G
authors.lastname: Gololobov
authors.forename: C A
authors.initials: CA
authors.lastname: Rumbley
authors.forename: J
authors.initials: J
authors.lastname: Rumbley
authors.forename: D V
authors.initials: DV
authors.lastname: Schourov
authors.forename: O I
authors.initials: OI
authors.lastname: Makarevich
authors.forename: A G
authors.initials: AG
authors.lastname: Gabibov
authors.forename: E W
authors.initials: EW
authors.lastname: Voss
mesh_terms: D000818:Animals; D000974:Antibodies, Antinuclear / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D017151:Antibodies, Catalytic / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D000911:Antibodies, Monoclonal / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D001483:Base Sequence; D001665:Binding Sites; D004247:DNA / Q000737:chemistry / Q000276:immunology* / Q000378:metabolism*; D006868:Hydrolysis; D066298:In Vitro Techniques; D007700:Kinetics; D051379:Mice; D008958:Models, Molecular; D009154:Mutation; D011487:Protein Conformation
chemical_list: D000974:Antibodies, Antinuclear; D017151:Antibodies, Catalytic; D000911:Antibodies, Monoclonal; D004247:DNA