Roles of arginyl residues in pyridoxamine-5'-phosphate oxidase from rabbit liver.
Roles of arginyl residues in pyridoxamine-5'-phosphate oxidase from rabbit liver.
复制标题
精氨酰残基在兔肝吡哆胺-5-磷酸氧化酶中的作用。
DOI：
10.1021/bi00523a014
复制
发表时间：
1981
期刊：
影响因子：
2.9
通讯作者：
McCormick,DB
中科院分区：
文献类型：
--
作者：
Choi,JD;McCormick,DB
Jung-Do Choi and Donald B. McCormick* abstract: Pyridoxamine-S'-phosphate oxidase (pyridoxine-5'-phosphate oxidase) is inactivated by arginine-specific reagents. Inactivation by phenylglyoxal follows pseudo-first-order kinetics and is first order with respect to modifier. The substrate-competitive inhibitors pyridoxal 5'-phosphate oxime and 4'-deoxypyridoxime 5'-phosphate and product py-ridoxal 5'-phosphate protect holoenzyme against inactivation but have no significant effect on the inactivationof apoenzyme. The extent of protection is dependent on their respective binding constants. Extrapolation to complete inactivation shows modification of~ 4 out of the 40 total arginyl residues in the native enzyme, with~ 1 residue protected by pyridoxal 5'-phosphate, as determined by incorporation of [7-14C]-phenylglyoxal. Binding of coenzyme flavin mononucleotide increases the rate of inactivation 3-fold by enhancing reactivity of an essential arginyl residue toward reagent. This and the
