Relative abundance and inhibitory distribution of protease inhibitors in potato juice from cv. Elkana.
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.
Pouvreau
L
L
Centre for Protein Technology, TNO-WU, P.O. Box 8129, 6700 EV Wageningen, The Netherlands.
Gruppen
H
H
Piersma
S R
SR
van den Broek
L A
LA
van Koningsveld
G A
GA
Voragen
A G
AG
D002918:Chymotrypsin / Q000037:antagonists & inhibitors; D013058:Mass Spectrometry; D011480:Protease Inhibitors / Q000145:classification / Q000302:isolation & purification*; D011198:Solanum tuberosum / Q000737:chemistry*; D014361:Trypsin Inhibitors
D011480:Protease Inhibitors; D014361:Trypsin Inhibitors; D002918:Chymotrypsin