Walsh T A, Twitchell W P
Agricultural Biotechnology Laboratory, DowElanco, 1701 Building, Midland, Michigan 48674.
Plant Physiol. 1991 Sep;97(1):15-8. doi: 10.1104/pp.97.1.15.
Two proteinase inhibitors have been isolated from tubers of potato (Solanum tuberosum). Based on N-terminal amino acid sequence homologies, they are members of the Kunitz family of proteinase inhibitors. Potato Kunitz inhibitor-1 (molecular weight 19,500, isoelectric point 6.9) is a potent inhibitor of the animal pancreatic proteinase trypsin, and its amino terminus has significant homology to a recently characterized cathepsin D Kunitz inhibitor from potato tubers (Mares et al. [1989] FEBS Lett 251:94-98). Potato Kunitz inhibitor-2 (molecular weight 20,500, isoelectric point 8.6) is an inhibitor of the microbial proteinase subtilisin Carlsberg; its amino terminus is almost identical to an abundant 22 kilodalton protein from potato tubers (Suh et al. [1990] Plant Physiol 94:40-45) and has significant homology to other Kunitz-type subtilisin inhibitors from small grains. Both Kunitz inhibitors are abundant proteins of the cortex of potato tubers.
已从马铃薯（茄属马铃薯）块茎中分离出两种蛋白酶抑制剂。基于N端氨基酸序列同源性，它们是Kunitz蛋白酶抑制剂家族的成员。马铃薯Kunitz抑制剂-1（分子量19,500，等电点6.9）是动物胰蛋白酶的有效抑制剂，其氨基末端与最近鉴定的来自马铃薯块茎的组织蛋白酶D Kunitz抑制剂具有显著同源性（Mares等人[1989] FEBS Lett 251:94-98）。马铃薯Kunitz抑制剂-2（分子量20,500，等电点8.6）是微生物蛋白酶枯草杆菌蛋白酶卡尔伯格的抑制剂；其氨基末端几乎与来自马铃薯块茎的一种丰富的22千道尔顿蛋白质相同（Suh等人[1990] Plant Physiol 94:40-45），并且与来自小粒谷物的其他Kunitz型枯草杆菌蛋白酶抑制剂具有显著同源性。两种Kunitz抑制剂都是马铃薯块茎皮层中的丰富蛋白质。
