89B-3 |
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F. J. CASTILLO, SR.1, R. Pacheco-Aguilar, Sr.2, F. L. Garcia-Carreño, Sr.3, M. D. L. A. Navarrete, and M. Felix-Lopez. (1) Food Chemistry, Univ. of Sonora, Boulevard Luis Encinas y Rosales s/n, Col. Centro, Hermosillo, 83000, Mexico, (2) Centro de Investigación en Alimentación y Desarrollo, Carr. La Victoria Km 0.6, Hermosillo, 83000, Mexico, (3) Seafood Biochemistry, Centro de Investigaciones Biológicas del Noroeste, La Paz, BCS, 23000, Mexico The Gulf of California, Mexico, is the habitat of a great variety of marine organisms, being Monterey sardine (Sardinops sagax caerulea ) the main commercial and industrialized fish from this Gulf. AProcessing sardines increases the wastes that are discarded directly into the sea, causing pollution. The viscera is one of the most important wastes of the sardine industry and this product is recognized with high potential as a source of digestive enzymes. Proteases from fish viscera could be used in industrial applications, so the recovery of this kind of waste might be an alternative to the pollution problem that the sardine industry produces. In this study, we present data on purification and the main biochemical characteristics of chymotrypsin from Monterey sardine viscera with the aim to contribute with alternatives for the commercial use of this by-product. Chymotrypsin was isolated from the viscera of Monterey sardine by ammonium sulphate fractionation, gel filtration and ionic exchange chromatography, and then it was characterized on its main biochemical features. The approximate molecular weight was 26,000 and its isoelectric point was about 5. The identity as chymotrypsin was established by its catalytic specificity for amide or ester bonds on the synthetic substrates Succinyl-L-Ala-Ala-Pro-L-Phe-p-nitroanilide and Benzoyl-L-Tyrosine ethyl-ester, showing esterase activity 3.2 times faster than amidase. It was inhibited by the serine protease inhibitors Phenylmethylsulfonyl fluoride and soybean trypsin inhibitor, partly inhibited by the specific chymotrypsin inhibitor N-Toluenesulfonyl-L-Phenylalanine chloromethyl-ketone, but was not inhibited by EDTA or benzamidine. Chymotrypsin showed its maximal activity at pH 8.0 and 50 °C for the hydrolysis of SAAPNA. The Michaelis-Menten constant was 0.074 mM and its catalysis constant was 18.6 seg-1, showing a catalytic efficiency of 252 seg-1 mM-1. Monterey sardine chymotrypsin is a good catalyst and could be used as a biotechnological tool in food processing.
Session 89B, Aquatic Food Products: Surimi, gels and by-products
2005 IFT Annual Meeting, July 15-20 - New Orleans, Louisiana |