Purification and Characterization of a Cysteine Protease Inhibitor from Chum Salmon (Oncorhynchus keta) Plasma

• Published in: Journal of agricultural and food chemistry 2008-01, Vol.56 (1), p.106-111
• Main Authors: Li, De Kun, Lin, Hong, Kim, Sang Moo
• Format: Article
• Language: English
• Subjects: Animals; bioactive constituent; Biological and medical sciences; blood plasma; characterization; Chromatography, Affinity; Chum salmon plasma; cysteine protease inhibitor; Cysteine Proteinase Inhibitors - blood; Cysteine Proteinase Inhibitors - classification; cysteine proteinases; Drug Stability; enzyme inhibition; Fish and seafood industries; Food industries; food processing; Fundamental and applied biological sciences. Psychology; Hot Temperature; Hydrogen-Ion Concentration; industrial applications; inhibitory activity staining; molecular weight; Oncorhynchus keta; Oncorhynchus keta - blood; papain; proteinase inhibitors; purification
• ISSN: 0021-8561; 1520-5118
• DOI: 10.1021/jf0723662

A cysteine protease inhibitor (CPI) in chum salmon (Oncorhynchus keta) plasma (CSP) was detected after performing inhibitory activity staining against papain under nonreducing condition. The CPI was purified from CSP by affinity chromatography with a yield and purification ratio of 0.94% and 30.36-fold, respectively. CSP CPI had a molecular mass of 70 kDa based on the results of SDS−PAGE and Sephacryl S-100 gel filtration. CSP CPI was a glycoprotein based on the periodic acid−Schiff (PAS) staining of the SDS−PAGE gel and classified as a kininogen. CSP CPI was stable in the pH range of 6.0–9.0 with maximal stability at pH 7.0. CSP CPI presented thermal stability at temperatures below 50 °C and exhibited maximal activity at temperatures of 20–40 °C. CSP CPI was determined to be a noncompetitive inhibitor against papain, with an inhibitor constant (K i) of 105 nM.