Nath R
Department of Physics, Kansas State University, Manhattan 66506.
Biochimie. 1993;75(6):467-72. doi: 10.1016/0300-9084(93)90112-6.
We have studied the specificity of Barrier, a protease secreted by Saccharomyces cerevisiae, towards its natural substrate alpha-factor, a tridecapeptide mating pheromone. Sub-fragments of alpha-factor synthesized or prepared by cyanogen bromide cleavage and a related pheromone from Saccharomyces kluveri were studied as potential substrates or competitive inhibitors. None of the tested peptides was a potent inhibitor or substrate for Barrier. Barrier shares extensive sequence similarity to the active site residues of aspartyl proteases but universal irreversible inhibitors of this class of enzymes failed to inactivate Barrier, suggesting that it is a novel fungal aspartyl protease.
我们研究了酿酒酵母分泌的蛋白酶Barrier对其天然底物α-因子（一种十三肽交配信息素）的特异性。通过溴化氰裂解合成或制备的α-因子亚片段以及来自克鲁维酵母的相关信息素被作为潜在底物或竞争性抑制剂进行研究。所测试的肽均不是Barrier的有效抑制剂或底物。Barrier与天冬氨酸蛋白酶的活性位点残基具有广泛的序列相似性，但这类酶的通用不可逆抑制剂未能使Barrier失活，这表明它是一种新型的真菌天冬氨酸蛋白酶。
