Proteinases for the gastric mucosa of the European sheatfish, Silurus glanis L
Ulitina, N.N.; Proskuriakov, M.T.
Prikladnaia Biokhimiia i Mikrobiologiia 40(1): 37-41
2004
ISSN/ISBN: 0555-1099 PMID: 15029695 Document Number: 583397
Three proteinases named as P1, P2 and P3, were isolated from European sheatfish (Silurus glanis L.) gastric mucosa by salting-out of (NH4)2SO4, gel-chromatography on Sephadex G-75 and ion-exchange chromatography on DEAE-cellulose. Isoelectric points of isolated proteinases were determined by isoelectric focusing and were equal to 1.9, 3.2 and 4.75 respectively for P1, P2 and P3. The molecular weight of P1 was 39,800 Da and proteinases P2 and P3 had a molecular weight of 30,200 Da. The optimum pH for three peptidases isolated from sheatfish gastric mucosa and maximum stability of these enzymes were found at acidic pH. It allowed identifying these proteinases as pepsin-type enzymes of fish.