title: Kunitz-type proteinase inhibitors from intact and Phytophthora-infected potato tubers.
abstract: 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.
authors.affiliation: A.N. Bakh Institute of Biochemistry, Russian Academy of Sciences, Moscow. inbio@glas.apc.org
authors.forename: T A
authors.initials: TA
authors.lastname: Valueva
authors.forename: T A
authors.initials: TA
authors.lastname: Revina
authors.forename: G V
authors.initials: GV
authors.lastname: Kladnitskaya
authors.forename: V V
authors.initials: VV
authors.lastname: Mosolov
mesh_terms: D000595:Amino Acid Sequence; D015853:Cysteine Proteinase Inhibitors / Q000302:isolation & purification*; D008969:Molecular Sequence Data; D008970:Molecular Weight; D010838:Phytophthora; D010935:Plant Diseases; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D015842:Serine Proteinase Inhibitors / Q000302:isolation & purification*; D011198:Solanum tuberosum / Q000201:enzymology*; D013379:Substrate Specificity
chemical_list: D015853:Cysteine Proteinase Inhibitors; D015842:Serine Proteinase Inhibitors