title: Characterization of a Mr = 56,000 polypeptide associated with 10S DNA polymerase alpha purified from calf thymus using monoclonal antibody.
abstract: Existence of a Mr = 56,000 polypeptide associated with 10S DNA polymerase alpha was shown by production of a monoclonal anti-calf thymus 10S DNA polymerase alpha antibody secreted from a hybridoma line named 3H1. The antibody bound three polypeptides with Mr = 180,000, 56,000 and 32,000 in hydroxylapatite fraction of 10S DNA polymerase alpha by immunoblot. The antibody co-precipitated the polypeptides with the large polypeptide (Mr = 150,000-140,000) of 10S DNA polymerase alpha with the aid of second antibody. Among three polypeptides, the Mr = 56,000 polypeptide was co-purified with DNA polymerase alpha through DNA-cellulose chromatography and repeated sucrose rate-zonal centrifugations. The Mr = 56,000 polypeptide was still associated with 10S DNA polymerase alpha after second sucrose rate-zonal centrifugation, but the amount of it was reduced. The polypeptide was banded at pH 7.2-8.0 and displayed microheterogeneity in respect of isoelectric point by isoelectrofocusing with 7 M urea, and showed weak DNA-binding property after blotting onto a nitrocellulose. The antibody against the polypeptide precipitated DNA polymerase alpha from human, rat, and mouse, and Mr = 56,000 and 32,000 polypeptides were detected in these DNA polymerase alpha fractions by immunoblot. These results suggest that the polypeptide with Mr = 56,000 may take part in the DNA polymerase reaction.
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal; D000936:Antigen-Antibody Complex; D002417:Cattle; D002999:Clone Cells; D004257:DNA Polymerase II / Q000276:immunology / Q000302:isolation & purification* / Q000378:metabolism; D019915:DNA Primase; D004591:Electrophoresis, Polyacrylamide Gel; D006825:Hybridomas / Q000276:immunology; D046911:Macromolecular Substances; D051379:Mice; D008970:Molecular Weight; D010455:Peptides / Q000276:immunology; D012316:RNA Nucleotidyltransferases / Q000302:isolation & purification / Q000378:metabolism; D013950:Thymus Gland / Q000201:enzymology*
chemical_list: D000911:Antibodies, Monoclonal; D000936:Antigen-Antibody Complex; D046911:Macromolecular Substances; D010455:Peptides; D019915:DNA Primase; D012316:RNA Nucleotidyltransferases; D004257:DNA Polymerase II