Purification and characterization of a cysteine protease inhibitor from chum salmon (Oncorhynchus keta) plasma.
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 degrees C and exhibited maximal activity at temperatures of 20-40 degrees C. CSP CPI was determined to be a noncompetitive inhibitor against papain, with an inhibitor constant (Ki) of 105 nM.
Li
De Kun
de K
College of Food Science and Engineering, Ocean University of China, Qingdao, China.
Lin
Hong
H
Kim
Sang Moo
SM
D000818:Animals; D002846:Chromatography, Affinity; D015853:Cysteine Proteinase Inhibitors / Q000097:blood* / Q000145:classification; D004355:Drug Stability; D006358:Hot Temperature; D006863:Hydrogen-Ion Concentration; D017685:Oncorhynchus keta / Q000097:blood*
D015853:Cysteine Proteinase Inhibitors