title: A deoxyribonucleic acid binding protein from KB cells which inhibits deoxyribonuclease activity on single-stranded DNA.
abstract: A deoxyribonuclease inhibitor has been purified from KB cells by chromatography on single-stranded DNA-cellulose. Polyacrylamide gel electrophoresis showed the purified preparation to contain two major polypeptides in sodium dodecyl sulfate, with molecular weights of 72,000 and 65,000, but only one major band (with a molecular weight of approximately 140,000) after electrophoresis under nondenaturing conditions. The protein inhibits the hydrolysis of single-stranded DNA by KB DNase, DNase I, DNase II, and nuclease S1, but has no effect on the hydrolysis of double-stranded DNA by these enzymes. The inhibitor causes a reduction in the rate of hydrolysis of DNA by the deoxyribonuclease, probably by reducing the effective concentration of substrate.
mesh_terms: D002352:Carrier Proteins / Q000494:pharmacology / Q000502:physiology*; D002460:Cell Line; D004277:DNA, Single-Stranded; D003851:Deoxyribonucleases / Q000037:antagonists & inhibitors*; D006801:Humans; D007700:Kinetics; D008970:Molecular Weight
chemical_list: D002352:Carrier Proteins; D004277:DNA, Single-Stranded; D003851:Deoxyribonucleases