title: Action of pancreatic DNase: requirements for activation of DNA as a template-primer for DNA polymerase.
abstract: Pancreatic DNase requires both Ca2+ and Mg2+ for its activity as measured by formation of an activated DNA template for in vitro DNA polymerase alpha assay and by the hyperchromic shift. Mn2+ can partially satisfy the Mg2+ requirement of the DNase for activation of DNA but the resulting template is only 50% as active in the DNA polymerase assay. When precautions are taken to avoid divalent ion contamination, pancreatic DNase is not active in the presence of Ca2+ or Mg2+ alone. analysis of the DNA by sucrose gradient centrifugation shows that only in the presence of Ca2+ plus Mg2+ or Mn2+ does pancreatic DNase produce extensive strand breaks in the DNA. The activated DNA template that yields maximal DNA polymerase activity is low molecular weight material of 30,000 to 50,000 daltons.
mesh_terms: D000818:Animals; D002118:Calcium / Q000494:pharmacology; D002417:Cattle; D004247:DNA; D004257:DNA Polymerase II / Q000378:metabolism*; D004259:DNA-Directed DNA Polymerase / Q000378:metabolism*; D003851:Deoxyribonucleases / Q000378:metabolism*; D004533:Egtazic Acid / Q000494:pharmacology; D004789:Enzyme Activation; D008274:Magnesium / Q000494:pharmacology; D010179:Pancreas / Q000201:enzymology; D013696:Temperature; D013698:Templates, Genetic
chemical_list: D004533:Egtazic Acid; D004247:DNA; D004257:DNA Polymerase II; D004259:DNA-Directed DNA Polymerase; D003851:Deoxyribonucleases; D008274:Magnesium; D002118:Calcium