Lowe D J, Barber M J, Pawlik R T, Bray R C
Biochem J. 1976 Apr 1;155(1):81-5. doi: 10.1042/bj1550081.
A new non-functional modified form of milk xanthine oxidase is described. This contains molybdenum in a quinquivalent state, which is resistant to both oxidation and reduction. The new species is derived from the native enzyme in a two-step process. The first step is the conversion into the desulpho form, via loss of the 'persulphide' sulphur, and the second involves reaction with ethylene glycol or other reagents. The species gives a characteristic Mo(V) electron-paramagnetic-resonance signal, without proton splittings, designated Resting II. This is virtually identical with signals reported previously from resting turkey liver xanthine dehydrogenase and rabbit liver aldehyde oxidase. The possibility is discussed that species Resting II, prepared with ethylene glycol, contains a -COCH2OH residue bound to a nitrogen ligand of molybdenum.
描述了一种新的无功能修饰形式的牛奶黄嘌呤氧化酶。它含有五价态的钼，对氧化和还原都具有抗性。新物种是通过两步过程从天然酶衍生而来的。第一步是通过“过硫化物”硫的损失转化为脱硫形式，第二步涉及与乙二醇或其他试剂反应。该物种给出了特征性的Mo(V)电子顺磁共振信号，没有质子分裂，称为静止II。这与先前从静止火鸡肝脏黄嘌呤脱氢酶和兔肝脏醛氧化酶报道的信号几乎相同。讨论了用乙二醇制备的静止II物种含有与钼的氮配体结合的-COCH2OH残基的可能性。
