title: The most abundant protease inhibitor in potato tuber (cv. Elkana) is a serine protease inhibitor from the Kunitz family.
abstract: The gene of the most abundant protease inhibitor in potato cv. Elkana was isolated and sequenced. The deduced amino acid sequence of this gene showed 98% identity with potato serine protease inhibitor (PSPI), a member of the Kunitz family. Therefore, the most abundant protease inhibitor was considered to be one of the isoforms of PSPI. The PSPI group represents approximately 22% of the total amount of proteins in potato cv. Elkana and is composed of seven different isoforms that slightly differ in isoelectric point. Antibodies were raised against the two most abundant isoforms of PSPI. The binding of these antibodies to PSPI isoforms and protease inhibitors from different groups of protease inhibitor in potato showed that approximately 70% of the protease inhibitors present in potato juice belong to the Kunitz family.
authors.affiliation: Centre for Protein Technology TNO-WU, P.O. Box 8129, 6700 EV Wageningen, The Netherlands.
authors.forename: Laurice
authors.initials: L
authors.lastname: Pouvreau
authors.forename: Harry
authors.initials: H
authors.lastname: Gruppen
authors.forename: Gerrit A
authors.initials: GA
authors.lastname: Van Koningsveld
authors.forename: Lambertus A M
authors.initials: LA
authors.lastname: Van Den Broek
authors.forename: Alphons G J
authors.initials: AG
authors.lastname: Voragen
mesh_terms: D000595:Amino Acid Sequence; D000906:Antibodies / Q000378:metabolism; D004591:Electrophoresis, Polyacrylamide Gel; D007527:Isoenzymes / Q000032:analysis / Q000737:chemistry / Q000235:genetics; D008969:Molecular Sequence Data; D020836:Protein Structure, Quaternary; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA; D020539:Sequence Analysis, Protein; D015842:Serine Proteinase Inhibitors / Q000032:analysis* / Q000737:chemistry / Q000235:genetics; D011198:Solanum tuberosum / Q000737:chemistry* / Q000235:genetics; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
chemical_list: D000906:Antibodies; D007527:Isoenzymes; D015842:Serine Proteinase Inhibitors