title: Purification and properties of guanylate kinase from baker's yeast.
abstract: Guanylate kinase (ATP:(d)GMP phosphotransferase, EC 2.7.4.8) was purified about 200-fold with 4% yield from baker's yeast. The enzyme preparation showed a single band on polyacrylamide gel electrophoresis and the molecular weight of the enzyme was calculated to be 25 000 by gel filtration. With ATP as a phosphate donor, the kinase used only GMP as a phosphate acceptor. Km values for ATP and GMP were 0.5 and 0.048 mM, respectively. The enzyme reacted optimally at pH 7.5. The enzyme was labile during storage at 4 degrees C and inactivation was prevented by 20% glycerol.
mesh_terms: D000255:Adenosine Triphosphate / Q000378:metabolism; D004591:Electrophoresis, Polyacrylamide Gel; D006157:Guanosine Monophosphate / Q000378:metabolism; D006162:Guanylate Cyclase / Q000302:isolation & purification*; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D008970:Molecular Weight; D012441:Saccharomyces cerevisiae / Q000201:enzymology*
chemical_list: D006157:Guanosine Monophosphate; D000255:Adenosine Triphosphate; D006162:Guanylate Cyclase