Mukherjee M
Can J Biochem Cell Biol. 1983 Nov;61(11):1228-32. doi: 10.1139/o83-158.
The trypsin inhibitor TI-2 produced by Streptomyces griseus Cal in a medium, containing beef extract and peptone as the nitrogen source, was purified by ammonium sulfate precipitation and gel filtration. Amino acid analysis showed that it contained hydroxyproline and carbohydrate whereas tyrosine, tryptophan, and cystine were absent. The composition of the inhibitor protein thus showed a similarity to collagen. Growth of the organism in a medium with gelatin as the sole nitrogen source resulted in the production of the same TI-2 inhibitor. Incubation of gelatin with either concentrated culture filtrate, trypsin, or chymotrypsin also yielded trypsin inhibitors. The product isolated from the in vitro incubation of gelatin with trypsin appeared to be the same as TI-2. To the author's knowledge, this is the first report that peptides obtained by enzymic hydrolyses of gelatin are trypsin inhibitors.
灰色链霉菌Cal在含有牛肉浸膏和蛋白胨作为氮源的培养基中产生的胰蛋白酶抑制剂TI-2，通过硫酸铵沉淀和凝胶过滤进行纯化。氨基酸分析表明，它含有羟脯氨酸和碳水化合物，而酪氨酸、色氨酸和胱氨酸不存在。因此，该抑制剂蛋白的组成与胶原蛋白相似。该生物体在以明胶作为唯一氮源的培养基中生长，会产生相同的TI-2抑制剂。将明胶与浓缩培养滤液、胰蛋白酶或糜蛋白酶一起孵育，也会产生胰蛋白酶抑制剂。从明胶与胰蛋白酶的体外孵育中分离出的产物似乎与TI-2相同。据作者所知，这是关于通过明胶酶解获得的肽是胰蛋白酶抑制剂的首次报道。
