含硫醇肽-血红素复合物作为细胞色素P-450的模型

Thiol-containing peptide-hemin complexes as models of cytochrome P-450.

作者信息

Sakurai H, Hatayama E, Yoshimura T, Maeda M, Tamura H, Kawasaki K

出版信息

Biochem Biophys Res Commun. 1983 Sep 15;115(2):590-7. doi: 10.1016/s0006-291x(83)80185-5.

Abstract

Nine different synthesized thiol tetra- and penta-peptides containing Cys-Ser, Cys-Thr, Cys-His, Cys-Tyr and Cys-Cys in the N- and C-terminals are proposed as new models of apo-P-450. The peptide-hemin complexes in the oxidized (Fe(III] form in solution were characterized by their optical and EPR spectra and found to show hydroxylation activity like that of P-450 enzymes on acetanilide. Although the EPR properties of the complex containing Cys-His and all complexes in the presence of pyridine were similar to those of P-450, the optical properties of these complexes were not completely similar to those of P-450. Based on these results, the sixth heme coordination site of P-450 was discussed.

摘要

提出了九种不同的合成硫醇四肽和五肽，它们在N端和C端含有半胱氨酸-丝氨酸、半胱氨酸-苏氨酸、半胱氨酸-组氨酸、半胱氨酸-酪氨酸和半胱氨酸-半胱氨酸，作为脱辅基P-450的新模型。溶液中氧化态（Fe(III)形式）的肽-血红素复合物通过其光学和电子顺磁共振光谱进行表征，发现其对乙酰苯胺表现出类似于P-450酶的羟基化活性。尽管含有半胱氨酸-组氨酸的复合物以及在吡啶存在下的所有复合物的电子顺磁共振性质与P-450相似，但这些复合物的光学性质与P-450并不完全相似。基于这些结果，对P-450的第六个血红素配位位点进行了讨论。