Ren W P, Ono H, Tuboi S
Department of Biochemistry, Yamagata University School of Medicine, Japan.
Biochem Biophys Res Commun. 1989 Aug 30;163(1):215-9. doi: 10.1016/0006-291x(89)92123-2.
When rat liver mitochondria that had imported a synthetic extrapeptide of ornithine aminotransferase (composed of 34 amino acids) were incubated at 25 degrees C, the extrapeptide in their matrix was degraded inside the mitochondria. The degradation of the extrapeptide did not depend on energy either inside or outside the mitochondria. The degrading activity was found exclusively in the mitochondrial soluble fraction and only inhibited by N-ethylmaleimide of eight protease-inhibitors tested. These observations show that the extrapeptide cleaved from the precursor of the mitochondrial protein in the mitochondria is degraded by some ATP-independent proteases inside the mitochondria.
当导入了鸟氨酸转氨酶合成外肽（由34个氨基酸组成）的大鼠肝脏线粒体在25℃下孵育时，其基质中的外肽在线粒体内被降解。外肽的降解既不依赖于线粒体内也不依赖于线粒体外的能量。降解活性仅在线粒体可溶性部分中发现，并且在所测试的8种蛋白酶抑制剂中仅被N-乙基马来酰亚胺抑制。这些观察结果表明，在线粒体中从线粒体蛋白前体切割下来的外肽被线粒体内一些不依赖ATP的蛋白酶降解。
