Bohley P, Seglen P O
Institute for Physiological Chemistry, University of Tübingen, Germany.
Experientia. 1992 Feb 15;48(2):151-7. doi: 10.1007/BF01923508.
Proteins sequestered by a non-selective bulk process within the lysosomes turn over with an apparent half-life of about 8 minutes and this rapid lysosomal proteolysis is initiated by endopeptidases, in particular by the cathepsins D and L. We describe also the cathepsins B and H which show mainly exopeptidase and only low endopeptidase activity. Especially cathepsin H is most probably the only lysosomal aminopeptidase in many cell types. Additionally, the properties of other mammalian lysosomal endo- and exopeptidases are compared. Finally, we discuss some of the conditions for the action of lysosomal proteases as the low intralysosomal pH, the high part of lysosomal thiol groups and the absence of intralysosomal proteinase inhibitors.
通过非选择性批量过程隔离在溶酶体内的蛋白质，其周转的表观半衰期约为8分钟，这种快速的溶酶体蛋白水解由内肽酶启动，特别是组织蛋白酶D和L。我们还描述了组织蛋白酶B和H，它们主要表现为外肽酶活性，内肽酶活性较低。特别是组织蛋白酶H很可能是许多细胞类型中唯一的溶酶体氨肽酶。此外，还比较了其他哺乳动物溶酶体内肽酶和外肽酶的特性。最后，我们讨论了溶酶体蛋白酶发挥作用的一些条件，如溶酶体内低pH值、溶酶体硫醇基团的高比例以及溶酶体内蛋白酶抑制剂的缺乏。
