Assignment of hyperfine‐shifted heme carbon resonances in ferricytochrome b 5

FEBS Letters

Lee, Kang-Bong¹  Kweon, Jeehye¹  Park, Hokoon¹ 

[1]Advanced Analysis Center, Korea Institute of Science and Technology, PO Box 131, Cheongryang, Seoul 130-650, South Korea

关键词: Cytochrome b 5;    Heme resonances;    Hyperfine shift;    13C NMR;   

DOI  :  10.1016/0014-5793(95)00500-9

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

The reverse detection heteronuclear multiple quantum coherence, HMQC, study of native bovine ferricytochrome b ₅ has provided the complete assignment of hyperfine shifted resonances of heme carbons attached proton(s). The dominant delocalized π-spin density to vinyl groups gives rise to contact shifts which have opposite direction for a carbon and its attached proton(s). The most hyperfine shifted ¹³C heme signals are mainly generated from 3rd heme pyrrole ring substituents which identifies that the molecular orbital for facile electron transfer is oriented to exposed heme edge. Magnetic/electronic asymmetry of heme induced by two axial His makes spread the hyperfine shifted heme carbon resonances over the range of 280 ppm at 25°C, which would be the more sensitive probe than those of proton resonances in characterizing the nature of heme electronic structure of ferricytochrome b ₅.

【 授权许可】

Unknown