Low molecular weight serine protease from the viscera of sardinelle ( Sardinella aurita) with collagenolytic activity: Purification and characterisation

• Published in: Food chemistry 2011-02, Vol.124 (3), p.788-794
• Main Authors: Hayet, Ben Khaled, Rym, Nasri, Ali, Bougatef, Sofiane, Ghorbel, Moncef, Nasri
• Format: Article
• Language: English
• Subjects: amino acid sequences; animal organs; animal tissue extracts; collagen; Collagenolytic activity; enzyme activity; Enzyme characterization; fish processing; fish waste; Low molecular weight protease; molecular weight; Purification; Sardinella aurita; Sardinelle; serine proteinases; Viscera
• ISSN: 0308-8146; 1873-7072
• DOI: 10.1016/j.foodchem.2010.06.096

A new low molecular weight (LMW) serine-protease from sardinelle ( Sardinella aurita) viscera was purified using ammonium sulphate precipitation and Sephadex G-100 gel filtration, with a 3.82-fold increase in specific activity. The molecular weight of the enzyme was estimated to be 14.2 kDa by SDS-PAGE. The optimum pH and temperature for the enzyme activity were around pH 8.0 and 60 °C, respectively. The purified protease was strongly inhibited by phenylmethylsulphonyl fluoride, a serine-protease inhibitor, and soybean trypsin inhibitor. The N-terminal amino acid sequence of the first 10 amino acids of the purified protease was APVQPCVVVI. This sequence showed low homology with several peptidases, suggesting that the enzyme is a new protease. Interestingly, the protease was found to cleave collagen type I and hydrolyze succinyl-L-Ala-L-Ala-L-Pro-L-Phe-p-nitroanilide (sAAPFpna), an amide substrate of chymotrypsin. Our findings indicate that the S. aurita protease is a new LMW enzyme with collagenolytic activity.