从醋酸钙不动杆菌中纯化L-天冬酰胺酶B及其性质
Purification and properties of L-asparaginase B from Acinetobacter calcoaceticus.
作者信息
Joner P E
出版信息
Biochim Biophys Acta. 1976 Jun 7;438(1):287-95. doi: 10.1016/0005-2744(76)90244-8.
L-Asparaginase (L-asparagine amidohydrolase, EC 3.5.1.1) B from Acinetobacter calcoaceticus has been purified by precipitation with streptomycin, chromatography on DEAE-cellulose and CM-cellulose, gel filtration on Agarose and chromatography on phosphocellulose. The molecular weight of the enzyme was found to be 130 000. The enzyme was rather insensitive to pH changes between 7 and 9. The Michaelis constant was 3-10(-3) M. Hg2+, Cu2+, and Ni2+ as well as high ionic strength inhibited the activity of the enzyme, whereas citrate seemed to stimulate the activity. The enzyme catalyzed the deamination of L-glutamine to about the same extent as L-asparagine. The temperature stability of the enzyme is also reported. The enzyme had a weak tumor inhibitory power.
从醋酸钙不动杆菌中纯化得到了L-天冬酰胺酶（L-天冬酰胺酰胺水解酶，EC 3.5.1.1）B，纯化方法包括用链霉素沉淀、在DEAE-纤维素和CM-纤维素上进行色谱分离、在琼脂糖上进行凝胶过滤以及在磷酸纤维素上进行色谱分离。发现该酶的分子量为130000。该酶在pH 7至9之间对pH变化相当不敏感。米氏常数为3×10⁻³ M。Hg²⁺、Cu²⁺和Ni²⁺以及高离子强度会抑制该酶的活性，而柠檬酸盐似乎会刺激其活性。该酶催化L-谷氨酰胺脱氨的程度与L-天冬酰胺大致相同。还报道了该酶的温度稳定性。该酶具有较弱的肿瘤抑制能力。
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