DNA hydrolysis by monoclonal autoantibody BV 04-01.
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.
Rodkey
L S
LS
Department of Pathology and Laboratory Medicine, University of Texas-Houston, Medical School, 7225-0708, USA.
Gololobov
G
G
Rumbley
C A
CA
Rumbley
J
J
Schourov
D V
DV
Makarevich
O I
OI
Gabibov
A G
AG
Voss
E W
EW
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
D000974:Antibodies, Antinuclear; D017151:Antibodies, Catalytic; D000911:Antibodies, Monoclonal; D004247:DNA