蛔虫肌肉线粒体中细胞色素的氧化还原电位：复合物II（琥珀酸-泛醌还原酶）中的高氧化还原电位细胞色素b558 。

Oxidation-reduction potentials of cytochromes in Ascaris muscle mitochondria: high-redox-potential cytochrome b558 in complex II (succinate-ubiquinone reductase).

作者信息

Takamiya S, Kita K, Matsuura K, Furushima R, Oya H

机构信息

Department of Parasitology, Juntendo University, School of Medicine, Tokyo Japan.

出版信息

Biochem Int. 1990 Sep;21(6):1073-80.

PMID:2080921

Abstract

Oxidation-reduction midpoint potentials (Ems) were determined at pH 7.0 for cytochromes in the anaerobic respiratory chain of Ascaris mitochondria by redox titration techniques. Cytochrome b558, which is associated with complex II that functions as fumarate reductase in the terminal step of the respiratory chain, was shown to have an Em of -34 mV in the isolated complex II and -54 mV in mitochondria. These values are much higher than the value of Ascaris cytochrome b558. In contrast, Ems of cytochromes C + C1 and cytochrome b559.5 were determined in situ to be 235 mV and 78 mV, respectively, which are comparable to those of their mammalian counterparts.

摘要

通过氧化还原滴定技术，在pH 7.0条件下测定了蛔虫线粒体厌氧呼吸链中细胞色素的氧化还原中点电位（Ems）。细胞色素b558与复合体II相关，在呼吸链的末端步骤中作为延胡索酸还原酶发挥作用。在分离的复合体II中，细胞色素b558的Em为-34 mV，在线粒体中为-54 mV。这些值远高于蛔虫细胞色素b558的值。相比之下，细胞色素C + C1和细胞色素b559.5的Ems原位测定分别为235 mV和78 mV，与它们的哺乳动物对应物相当。