Light‐induced oxidation of iron atoms in a photosensitive nitrile hydratase

FEBS Letters

Ambe, Fumitoshi³  Hirata, Akira¹  Nagamune, Teruyuki²  Sasabe, Hiroyuki²  Endo, Isao⁴  Kobayashi, Yoshio³  Honda, Jun²  Teratani, Yoshitaka¹ 

[1] School of Science and Engineering, Waseda University, Shinjuku-ku, Tokyo 169, Japan;Frontier Research Program, RIKEN Institute, Wako-Shi, Saitama 351-01, Japan;Nuclear Chemistry Laboratory, RIKEN Institute, Wako-shi, Saitama 351-01, Japan;Chemical Engineering Laboratory, RIKEN Institute, Wako-shi, Saitama 351-01, Japan

关键词: Nitrile hydratase;    Mössbauer spectroscopy;    Magnetic susceptibility;    Photoactivation;    Oxidation;    Non-heme iron;    NHase;    nitrile hydratase;    SQUID;    superconducting quantum interference device;   

DOI  :  10.1016/0014-5793(92)81242-E

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

The photoactivation process of a photosensitive nitrile hydratase (NHase) from Rhodococcus sp. N-771 has been investigated by ⁵⁷Fe Mössbauer spectroscopy and magnetic susceptibility measurements in order to clarify the behavior of iron atoms in the enzyme. Mössbauer spectra of inactive NHase gave two symmetric-doublet components indicating the presence of two iron species, while that of the active NHase gave a single symmetric doublet indicating the presence of a single iron species. Magnetic susceptibility measurements of the inactive and active HNase both showed small effective magnetic moments. These results led us to conclude that one of the two iron atoms incorporated in the NHase is oxidized during photoactivation, namely from a low spin ferrous to a low spin ferric state. This is the first observation of an intramolecular photooxidation phenomena involving iron in a single protein molecule.

【 授权许可】

Unknown