title: Effect of ribonucleotides on substrate availability for DNA polymerase assays in cytoplasmic fractions of rat intestinal mucosa.
abstract: The deoxyribonucleoside triphosphate substrates for DNA synthesis were hydrolysed during the DNA polymerase (EC 2.7.7.7) assay with cytoplasmic subcellular fractions of rat intestinal mucosa. Presumably because of phosphatase (EC 3.1.3.2) activity in these fractions, inorganic phosphate was liberated from the nucleotides, and radioactive thymidine triphosphate was shown to be degraded to thymidine di-and mono-phosphate, thymidine, and thymine. Addition of ATP to the postmicrosomal supernatant increased its DNA polymerase activity by sparing the deoxyribonucleotide precursors from enzymatic degradation.
mesh_terms: D000135:Acid Phosphatase / Q000378:metabolism; D000255:Adenosine Triphosphate / Q000494:pharmacology; D000818:Animals; D004259:DNA-Directed DNA Polymerase / Q000378:metabolism*; D003854:Deoxyribonucleotides; D007413:Intestinal Mucosa / Q000201:enzymology*; D007700:Kinetics; D008861:Microsomes / Q000201:enzymology; D051381:Rats; D013347:Subcellular Fractions / Q000201:enzymology
chemical_list: D003854:Deoxyribonucleotides; D000255:Adenosine Triphosphate; D004259:DNA-Directed DNA Polymerase; D000135:Acid Phosphatase