Relative Abundance and Inhibitory Distribution of Protease Inhibitors in Potato Juice from cv. Elkana

• Published in: Journal of agricultural and food chemistry Vol. 49; no. 6; pp. 2864 - 2874
• Main Authors: Pouvreau, L, Gruppen, H, Piersma, S. R, van den Broek, L. A. M, van Koningsveld, G. A, Voragen, A. G. J
• Format: Journal Article
• Language: English
• Published: Washington, DC American Chemical Society 01.06.2001
• Subjects: Animal, plant, fungal and microbial proteins, edible seaweeds and food yeasts; Biological and medical sciences; Chymotrypsin - antagonists & inhibitors; Food Chemistry; Food Chemistry Group; Food industries; Fundamental and applied biological sciences. Psychology; Leerstoelgroep Levensmiddelenchemie; Levensmiddelenchemie; Mass Spectrometry; Protease Inhibitors - classification; Protease Inhibitors - isolation & purification; Solanum tuberosum - chemistry; Trypsin Inhibitors; VLAG; Fractionation; Serine endopeptidases; Enzyme; Solanum tuberosum; Vegetable juice; Peptidases; Chymotrypsin; Trypsin; Enzymatic activity; Dicotyledones; Angiospermae; Hydrolases; Spermatophyta; Solanaceae; Tuber plant; Protease inhibitor; Quantitative analysis; Cultivar
• ISSN: 0021-8561; 1520-5118
• DOI: 10.1021/jf010126v

Protease inhibitors from potato juice of cv. Elkana were purified and quantified. The protease inhibitors represent ca. 50% of the total soluble proteins in potato juice. The protease inhibitors were classified into seven different families:  potato inhibitor I (PI-1), potato inhibitor II (PI-2), potato cysteine protease inhibitor (PCPI), potato aspartate protease inhibitor (PAPI), potato Kunitz-type protease inhibitor (PKPI), potato carboxypeptidase inhibitor (PCI), and “other serine protease inhibitors”. The most abundant families were the PI-2 and PCPI families, representing 22 and 12% of all proteins in potato juice, respectively. Potato protease inhibitors show a broad spectrum of enzyme inhibition. All the families (except PCI) inhibited trypsin and/or chymotrypsin. PI-2 isoforms exhibit 82 and 50% of the total trypsin and chymotrypsin inhibiting activity, respectively. A strong variation within the latter activities was shown within one family and between protease inhibitor families. Keywords: Potato; Solanum tuberosum; protease inhibitor; inhibiting activity; trypsin; chymotrypsin