title: Deoxycytidylate deaminase. Properties of the enzyme from cultured kidney cells of baby hamster.
abstract: dCMP deaminase was partially purified from BHK-21/C13 cells grown in culture. The molecular weight of the enzyme was estimated by gel filtration and gradient centrifugation to be 130000 and 115000 respectively. The enzyme had a pH optimum of 8.4. Its activity versus substrate concentration curve was sigmoid, the substrate concentration at half-maximal velocity being 4.4mm. dCTP activated the deaminase maximally at 40mum, gave a hyperbolic curve for activity versus dCMP concentration and a K(m) value for dCMP of 0.91mm. dCTP activation required the presence of Mg(2+) or Mn(2+) ions. dTTP inhibited the deaminase maximally at 15mum; the inhibition required the presence of Mg(2+) or Mn(2+) ions. The enzyme was very heat-labile but could be markedly stabilized by dCTP at 0.125mm and ethylene glycol at 20% (v/v).
mesh_terms: D000619:Aminohydrolases / Q000037:antagonists & inhibitors; D000818:Animals; D002460:Cell Line; D002499:Centrifugation, Density Gradient; D002848:Chromatography, DEAE-Cellulose; D002850:Chromatography, Gel; D006224:Cricetinae; D046508:Culture Techniques; D003597:Cytosine Nucleotides; D003854:Deoxyribonucleotides; D005030:Ethylenes; D006018:Glycols; D006863:Hydrogen-Ion Concentration; D007668:Kidney / Q000201:enzymology; D007700:Kinetics; D008274:Magnesium / Q000378:metabolism; D008345:Manganese / Q000378:metabolism; D008970:Molecular Weight; D013696:Temperature; D013942:Thymine Nucleotides
chemical_list: D003597:Cytosine Nucleotides; D003854:Deoxyribonucleotides; D005030:Ethylenes; D006018:Glycols; D013942:Thymine Nucleotides; D008345:Manganese; D000619:Aminohydrolases; D008274:Magnesium