کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
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1188628 | 963493 | 2009 | 8 صفحه PDF | دانلود رایگان |
Two trypsins (A and B) from the intestine of skipjack tuna (Katsuwonus pelamis) were purified by Sephacryl S-200, Sephadex G-50 and DEAE-cellulose with a 177- and 257-fold increase in specific activity and 23% and 21% recovery for trypsin A and B, respectively. Purified trypsins revealed a single band on native-PAGE. The molecular weights of both trypsins were 24 kDa as estimated by size exclusion chromatography and SDS–PAGE. Trypsin A and B exhibited the maximal activity at 55 °C and 60 °C, respectively, and had the same optimal pH at 9.0. Both trypsins were stable up to 50 °C and in the pH range from 6.0 to 11.0. Both trypsin A and B were stabilised by calcium ion. Activity of both trypsins continuously decreased with increasing NaCl concentration (0–30%) and were inhibited by the specific trypsin inhibitors – soybean trypsin inhibitor and N-p-tosyl-l-lysine chloromethyl ketone. Apparent Km and Kcat of trypsin A and B were 0.22–0.31 mM and 69.5–82.5 S−1, respectively. The N-terminal amino acid sequences of the first 20 amino acids of trypsin A and B were IVGGYECQAHSQPPQVSLNA and IVGGYECQAHSQPPQVSLNS, respectively.
Journal: Food Chemistry - Volume 115, Issue 1, 1 July 2009, Pages 155–162