An amidase from a strain Bacillus cereus ZJB-07112 was purified to homogeneity by using sonication, anion-exchange chromatography, phenyl-sepharose chromatography.The molecular weight of amidase was estimated to be 60...An amidase from a strain Bacillus cereus ZJB-07112 was purified to homogeneity by using sonication, anion-exchange chromatography, phenyl-sepharose chromatography.The molecular weight of amidase was estimated to be 60.6×103 by 12.5% SDS-PAGE.Its N-terminal sequence was ATIRPDDKAI.The optimum pH and temperature of the amidase for acrylamide were pH 7.5 and 35℃, respectively.The enzyme was unstable at a temperature over 50℃ and only 10.8% activity was retained after exposure to 60℃ for 30 min.Most of metal ions and EDTA had no significant effect on the enzyme activity, whereas Hg+,Ag+ and urea caused obvious inhibition.The Km and Vmax values of the amidase for acrylamide were 2.64 mmol·L-1 and 0.6 μmol·min-1·ml-1, respectively.展开更多
文摘An amidase from a strain Bacillus cereus ZJB-07112 was purified to homogeneity by using sonication, anion-exchange chromatography, phenyl-sepharose chromatography.The molecular weight of amidase was estimated to be 60.6×103 by 12.5% SDS-PAGE.Its N-terminal sequence was ATIRPDDKAI.The optimum pH and temperature of the amidase for acrylamide were pH 7.5 and 35℃, respectively.The enzyme was unstable at a temperature over 50℃ and only 10.8% activity was retained after exposure to 60℃ for 30 min.Most of metal ions and EDTA had no significant effect on the enzyme activity, whereas Hg+,Ag+ and urea caused obvious inhibition.The Km and Vmax values of the amidase for acrylamide were 2.64 mmol·L-1 and 0.6 μmol·min-1·ml-1, respectively.
