Mechler B, Müller H, Wolf D H
Biochemisches Institut, Universität Freiburg, FRG.
EMBO J. 1987 Jul;6(7):2157-63. doi: 10.1002/j.1460-2075.1987.tb02483.x.
Studies were performed to unravel the activation and maturation mechanism of vacuolar (lysosomal) proteinases in Saccharomyces cerevisiae. In vivo and in vitro studies show that proteinase yscA and proteinase yscB are involved in the activation and processing event of pro-carboxypeptidase yscY. Processing and activation of pro-carboxypeptidase yscY by proteinase yscA depends on an additional factor contained in the vacuolar fraction. Comparable activation can be mimicked by sodium polyphosphate. Optimum pH for processing by this proteinase yscA-triggered event is 5. The proteinase yscA-triggered maturation process of pro-carboxypeptidase yscY leads to an intermediate mol. wt form of the enzyme which is, however, fully active. Proteinase yscB transfers the intermediate mol. wt form of the original precursor to the apparently authentic, mature and active carboxypeptidase yscY. An activation and maturation scheme is devised.
开展了多项研究以阐明酿酒酵母中液泡（溶酶体）蛋白酶的激活和成熟机制。体内和体外研究表明，蛋白酶yscA和蛋白酶yscB参与了羧肽酶原yscY的激活和加工过程。蛋白酶yscA对羧肽酶原yscY的加工和激活依赖于液泡组分中所含的另一种因子。聚磷酸钠可模拟类似的激活作用。该蛋白酶yscA触发事件进行加工的最适pH为5。蛋白酶yscA触发的羧肽酶原yscY成熟过程产生一种中间分子量形式的酶，然而该酶具有完全活性。蛋白酶yscB将原始前体的中间分子量形式转化为明显真实、成熟且有活性的羧肽酶yscY。设计了一种激活和成熟方案。
