假单胞菌细胞色素中的电子自交换。

Electron self-exchange in Pseudomonas cytochromes.

作者信息

Timkovich R, Cai M L, Dixon D W

机构信息

Department of Chemistry, University of Alabama, Tuscaloosa 35487.

出版信息

Biochem Biophys Res Commun. 1988 Feb 15;150(3):1044-50. doi: 10.1016/0006-291x(88)90735-8.

DOI:10.1016/0006-291x(88)90735-8

PMID:2829889

Abstract

Electron self-exchange has been measured by an NMR technique for cytochromes c551 from Pseudomonas aeruginosa and Pseudomonas stutzeri. The rate for P. aeruginosa cyt c551 is 1.2 x 10(7) M-1 s-1 at 40 degrees C in 50 mM phosphate at pH 7. For P. stutzeri, under the same conditions, the rate is 4 x 10(7) M-1 s-1. For both cytochromes, the rate was independent of ionic strength up to 0.5 M in added NaC1, the enthalpy of activation was 20 +/- 4 kcal mol-1, and the entropy of activation was 38 +/- 10 cal mol-1 deg-1.

摘要

已通过核磁共振技术测定了铜绿假单胞菌和施氏假单胞菌细胞色素c551的电子自交换。在40℃、pH值为7的50mM磷酸盐中，铜绿假单胞菌细胞色素c551的交换速率为1.2×10⁷M⁻¹s⁻¹。在相同条件下，施氏假单胞菌的速率为4×10⁷M⁻¹s⁻¹。对于这两种细胞色素，在添加氯化钠至0.5M时，速率与离子强度无关，活化焓为20±4kcal mol⁻¹，活化熵为38±10cal mol⁻¹deg⁻¹。