Heme‐linked ionization and ligand binding produce identical changes of proximal heme stereochemistry in reduced horseradish peroxidase Evidence for existence of two protein conformations

FEBS Letters

Sharonov, Yurii A.¹  Pismensky, Victor F.¹  Yarmola, Elena G.¹ 

[1] Institute of Molecular Biology, Academy of Sciences of the USSR, 117984 Moscow, USSR

关键词: Horseradish peroxidase;    Protoheme-(2-MeIm);    Carbon monoxide;    Photolysis;    Heme stereochemistry;    Magnetic circular dichroism;    HRP;    horseradish peroxidase;    Mb;    myoglobin;    His;    histidine;    2-MeIm;    2-methylimidazole;    MCD;    magnetic circular dichroism;    RR;    resonance Raman;   

DOI  :  10.1016/0014-5793(88)81234-1

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

The visible and near infrared magnetic circular dichroism spectra of chemically reduced horseradish peroxidase at neutral and alkaline pH values and 5-coordinate protoheme-(2-methylimidazole) at pH 9.1 were compared at 4.2 K with those of photolysis products of their carbon monoxide complexes. From the results obtained we concluded that: (i) there are two protein conformations of HRP which determine the geometry of the Fe-N(His) bond; (ii) the transition from one conformation (heme stereochemistry) to another can be induced by either heme-linked ionization or ligand binding; (iii) a trigger mechanism for switching between two conformations has to exist.

【 授权许可】

Unknown