Heme maintains catalytically active structure of cytochrome P‐450

FEBS Letters

Tretiakov, V.E.²  Archakov, A.I.¹  Uvarov, V.Yu.¹ 

[1] 2nd Moscow Medical Institute, Department of Biochemistry, Ostrovitjanova 1, Moscow 117437 USSR;Institute of Physico-Chemical Medicine, Moscow 119828, USSR

关键词: Cytochrome P-450;    Apoenzyme;    Heme;    Secondary structure;    Hydrogen peroxide;   

DOI  :  10.1016/0014-5793(90)80131-2

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Treatment of purified cytochrome P-450 LM2 and its liposome-bound form with hydrogen peroxide led to complete destruction of the P-450 heme. The apoenzyme thus produced could be reconstituted to catalytically active cytochrome P-450 by incubation with hemin, the reconstitution efficiency being 50% for the soluble enzyme and 80% for the liposome-bound enzyme. The removal of heme from the soluble hemoprotein resulted in a 3-fold decrease in the efficiency of its incorporation into sonicated liposomes. The contents of 5 secondary structure forms in the native, apoand reconstituted holoenzymes were estimated from their circular dichroism spectra. It was thus found that the helix content increased from 34% to 60% upon removal of the heme from the native enzyme. We suggest that the increase in the helix content leads to a reduction of the incorporation efficiency into liposomal membranes.

【 授权许可】

Unknown