Valueva T A, Revina T A, Kladnitskaya G V, Mosolov V V
A.N. Bakh Institute of Biochemistry, Russian Academy of Sciences, Moscow.
FEBS Lett. 1998 Apr 10;426(1):131-4. doi: 10.1016/s0014-5793(98)00321-4.
Three protein proteolytic enzyme inhibitors with molecular masses 21, 22, and 23 kDa have been isolated from intact potato tubers (Solanum tuberosum L. cv. Istrinskii). The 21 and 22 kDa proteins denoted as PSPI-21 and PSPI-22, respectively, are serine proteinase inhibitors with different specificity. The 23 kDa protein denoted as PCPI-23 is an inhibitor of plant cysteine proteinases. The PSPI-21 molecule consists of two disulfide-linked polypeptide chains with molecular masses of 16.5 kDa and 4.5 kDa. The PSPI-22 and PCPI-23 have one polypeptide chain. Their amino-termini numbered 21-25 amino acid residues have significant homology to other plant inhibitors which are members of the soybean Kunitz inhibitor family. It is found that at least PSPI-21 and PSPI-22 can predominantly accumulate in potato tubers infected with Phytophthora infestans zoospores.
已从完整的马铃薯块茎（茄属马铃薯L.品种Istrinskii）中分离出三种分子量分别为21、22和23 kDa的蛋白质水解酶抑制剂。这两种分子量为21 kDa和22 kDa的蛋白质分别命名为PSPI-21和PSPI-22，它们是具有不同特异性的丝氨酸蛋白酶抑制剂。分子量为23 kDa的蛋白质命名为PCPI-23，是植物半胱氨酸蛋白酶的抑制剂。PSPI-21分子由两条通过二硫键连接的多肽链组成，分子量分别为16.5 kDa和4.5 kDa。PSPI-22和PCPI-23各有一条多肽链。它们编号为21 - 25个氨基酸残基的氨基末端与大豆Kunitz抑制剂家族成员的其他植物抑制剂具有显著同源性。研究发现，至少PSPI-21和PSPI-22能在被致病疫霉游动孢子感染的马铃薯块茎中大量积累。
