CYTOCHROME-OXIDASE FROM PSEUDOMONAS-AERUGINOSA .1. PURIFICATION AND SOME PROPERTIES
CYTOCHROME-OXIDASE FROM PSEUDOMONAS-AERUGINOSA .1. PURIFICATION AND SOME PROPERTIES
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DOI：
10.1016/0005-2728(73)90044-3
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发表时间：
1973-01-01
期刊：
影响因子：
--
通讯作者：
WHARTON, DC
中科院分区：
文献类型：
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作者：
GUDAT, JC;SINGH, J;WHARTON, DC
A new purification procedure for the isolation ofPseudomonascytochrome oxidase (ferrocytochromec2:O2oxidoreductase, EC 1.9.3.2) is described. The product is purified 16-fold over the crude cell extract and contains equimolar amounts of hemecand hemed.The molecular weight of the electrophoretically homogeneous enzyme is about 121200 as determined by sedimentation equilibrium. Acrylamide gel electrophoresis in the presence of sodium dodecyl sulfate results in a single proteinstaining band with a molecular weight of 58000. The minimal molecular weight on the basis of heme-iron content is 55600.With O2as the final electron acceptor and at 30 °C in 0.1 M phosphate at the optimum pH of 6.0 theKmfor reducedPseudomonascytochromec-551 as substrate is 10.5 μM whereas withPseudomonascopper protein as the electron source theKmis 17.2 μM under identical conditions.The absorption spectrum of purifiedPseudomonascytochrome oxidase shows maxima at 640, 525 and 412 nm in the oxidized state and at 625–655, 544, 549, 521, 460 and 418 nm in the reduced state.The EPR spectrum taken at 10 °K has signals withgvalues of 4.30, 2.93, 2.45, 2.31, 2.08, 1.71 and 1.4. Evidence indicates that those signals atg= 2.93, 2.31 and 1.4 arise from the hemecwhile those atg= 2.45 and 1.71 arise from hemed. No signals can be seen after reduction of the enzyme.
