[Properties of polyphosphate phosphohydrolase of the "leaky" mutant Neurospora crassa with respect to the specific enzyme].
Some properties of polyphosphate phosphohydrolase from N. crassa strain ad-6.28610a and from its mutant with a decreased polyphosphate phosphohydrolase activity were compared. It was shown that the pH optimum for both enzyme species lies within the range of 7.1-7.3; the temperature optimum is 45 degrees. The mutant polyphosphate phosphohydrolase has a V value, which is 2 times less than that of the parent strain, and possesses a higher thermal inactivation stability. The enzymes of both cultures have practically identical values of Km(app), which depend on the length of the substrate chain. Upon transition from polyphosphate n = 9 to polyphosphate n = 180 the enzyme affinity is increased. Electrophoretic separation of cell-free extract proteins in polyacrylamide gel revealed the existence of two enzyme isoforms in both strains. The electrophoretic mobility of these isoforms are identical in both cultures. Biosynthesis of polyphosphate phosphohydrolase and tripolyphosphatase of N. crassa, unlike that of bacteria, is not controlled by a system common for alkaline phosphatase.
D017766:Acid Anhydride Hydrolases; D004355:Drug Stability; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D009154:Mutation; D009491:Neurospora / Q000201:enzymology*; D009492:Neurospora crassa / Q000201:enzymology*; D010744:Phosphoric Monoester Hydrolases / Q000378:metabolism*
D010744:Phosphoric Monoester Hydrolases; D017766:Acid Anhydride Hydrolases; C020137:exopolyphosphatase
Izuchenie svoĭstv polifosfatfosfogidrolazy "leaky" mutanta Neurospora crassa po dannomu fermentu.