Watabe S, Hasegawa H, Takimoto K, Yamamoto Y, Takahashi S Y
Radioisotope Laboratory, Faculty of Agriculture, Yamaguchi University, Japan.
Biochem Biophys Res Commun. 1995 Aug 24;213(3):1010-6. doi: 10.1006/bbrc.1995.2229.
SP-22 was found to be a substrate protein of a mitochondrial ATP-dependent protease in bovine adrenal cortex. Its amino acid sequence was homologous to that of some prokaryotic and eukaryotic proteins such as thioredoxin peroxidase (formerly called thiol-specific antioxidant) in yeast and mammalian brains and the C22 component of alkyl hydroperoxide reductase in Salmonella typhimurium. In the present study, we found SP-22 to have the ability to scavenge reactive oxygen species, thus protecting radical-sensitive proteins such as tryptophan hydroxylase, glutamine synthetase and hemoglobin from oxidation. The protecting activity was enhanced by the addition of horse serum. The "serum factor(s)" seemed to be protein(s), since the physiological roles of SP-22 in adrenocortical mitochondria are discussed.
在牛肾上腺皮质中，SP - 22被发现是一种线粒体ATP依赖性蛋白酶的底物蛋白。它的氨基酸序列与一些原核和真核蛋白同源，如酵母和哺乳动物大脑中的硫氧还蛋白过氧化物酶（以前称为硫醇特异性抗氧化剂）以及鼠伤寒沙门氏菌中烷基过氧化氢还原酶的C22组分。在本研究中，我们发现SP - 22具有清除活性氧的能力，从而保护色氨酸羟化酶、谷氨酰胺合成酶和血红蛋白等对自由基敏感的蛋白质不被氧化。添加马血清可增强这种保护活性。由于讨论了SP - 22在肾上腺皮质线粒体中的生理作用，“血清因子”似乎是蛋白质。
