Purification and characterization of a dimethoate-degrading enzyme of Aspergillus niger ZHY256, isolated from sewage.
A dimethoate-degrading enzyme from Aspergillus niger ZHY256 was purified to homogeneity with a specific activity of 227.6 U/mg of protein. The molecular mass of the purified enzyme was estimated to be 66 kDa by gel filtration and 67 kDa by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The isoelectric point was found to be 5.4, and the enzyme activity was optimal at 50 degrees C and pH 7.0. The activity was inhibited by most of the metal ions and reagents, while it was induced by Cu(2+). The Michaelis constant (K(m)) and V(max) for dimethoate were 1.25 mM and 292 micromol min(-1) mg of protein(-1), respectively.
Liu
Y H
YH
State Key Laboratory for Biocontrol, School of Life Science, Zhong Shan University, Guang Zhou 510275, People's Republic of China. Lsslyh@zsu.edu.cn
Chung
Y C
YC
Xiong
Y
Y
D001234:Aspergillus niger / Q000201:enzymology* / Q000302:isolation & purification; D004117:Dimethoate / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration; D006867:Hydrolases / Q000737:chemistry / Q000302:isolation & purification* / Q000378:metabolism*; D007306:Insecticides / Q000378:metabolism*; D012722:Sewage / Q000382:microbiology*; D013379:Substrate Specificity; D013696:Temperature
D007306:Insecticides; D012722:Sewage; D006867:Hydrolases; C437624:dimethoate-degrading enzyme; D004117:Dimethoate