质膜电子传递中辅酶Q的需求
Requirement for coenzyme Q in plasma membrane electron transport.
作者信息
Sun I L, Sun E E, Crane F L, Morré D J, Lindgren A, Löw H
机构信息
Department of Biological Sciences, Purdue University, West Lafayette, IN 47907.
出版信息
Proc Natl Acad Sci U S A. 1992 Dec 1;89(23):11126-30. doi: 10.1073/pnas.89.23.11126.
Coenzyme Q is required in the electron transport system of rat hepatocyte and human erythrocyte plasma membranes. Extraction of coenzyme Q from the membrane decreases NADH dehydrogenase and NADH:oxygen oxidoreductase activity. Addition of coenzyme Q to the extracted membrane restores the activity. Partial restoration of activity is also found with alpha-tocopherylquinone, but not with vitamin K1. Analogs of coenzyme Q inhibit NADH dehydrogenase and oxidase activity and the inhibition is reversed by added coenzyme Q. Ferricyanide reduction by transmembrane electron transport from HeLa cells is inhibited by coenzyme Q analogs and restored with added coenzyme Q10. Reduction of external ferricyanide and diferric transferrin by HeLa cells is accompanied by proton release from the cells. Inhibition of the reduction by coenzyme Q analogs also inhibits the proton release, and coenzyme Q10 restores the proton release activity. Trans-plasma membrane electron transport stimulates growth of serum-deficient cells, and added coenzyme Q10 increases growth of HeLa (human adenocarcinoma) and BALB/3T3 (mouse fibroblast) cells. The evidence is consistent with a function for coenzyme Q in a trans-plasma membrane electron transport system which influences cell growth.
辅酶Q是大鼠肝细胞和人红细胞质膜电子传递系统所必需的。从膜中提取辅酶Q会降低NADH脱氢酶和NADH：氧氧化还原酶的活性。向提取的膜中添加辅酶Q可恢复活性。α-生育酚醌也能使活性部分恢复，但维生素K1则不能。辅酶Q类似物会抑制NADH脱氢酶和氧化酶的活性，而添加辅酶Q可逆转这种抑制作用。辅酶Q类似物会抑制HeLa细胞跨膜电子传递导致的铁氰化物还原，添加辅酶Q10可恢复该还原作用。HeLa细胞还原细胞外铁氰化物和二价铁转铁蛋白时伴随着质子从细胞中释放。辅酶Q类似物对还原作用的抑制也会抑制质子释放，而辅酶Q10可恢复质子释放活性。跨质膜电子传递会刺激血清缺乏细胞的生长，添加辅酶Q10可促进HeLa（人腺癌）细胞和BALB/3T3（小鼠成纤维细胞）的生长。这些证据表明辅酶Q在影响细胞生长的跨质膜电子传递系统中发挥作用。
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