Table of Contents
Journal of Amino Acids
Volume 2011, Article ID 728082, 7 pages
http://dx.doi.org/10.4061/2011/728082
Research Article

Mackerel Trypsin Purified from Defatted Viscera by Supercritical Carbon Dioxide

1Department of Food Science and Technology, Pukyong National University, Busan 608-737, Republic of Korea
2Research Faculty of Fisheries Sciences, Hokkaido University, Hakodate, Hokkaido 041-8611, Japan
3Faculty of Agro-Industry, King Mongkut's Institute of Technology Ladkrabang, Choakhunthaharn Building, Choakhunthaharn Rd., Ladkrabang, Bangkok 10520, Thailand
4Department of Food Technology, Faculty of Agro-Industry, Prince of Songkla University, Hat Yai, Songkhla 90112, Thailand
5Department of Food Science and Technology, Faculty of Technology and Community Development, Thaksin University, Phattalung Campus, Phattalung 93110, Thailand

Received 22 February 2011; Accepted 10 May 2011

Academic Editor: Moncef Nasri

Copyright © 2011 Byung-Soo Chun et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Viscera of mackerel (Scomber sp.) were defatted by supercritical carbon dioxide (SCO2) treatment. Trypsin (SC-T) was then extracted from the defatted powder and purified by a series of chromatographies including Sephacryl S-200 and Sephadex G-50. The purified SC-T was nearly homogeneous on SDS-PAGE, and its molecular weight was estimated as approximately 24,000 Da. N-terminal twenty amino acids sequence of SC-T was IVGGYECTAHSQPHQVSLNS. The specific trypsin inhibitors, soybean trypsin inhibitor and TLCK, strongly inhibited the activities of SC-T. The pH and temperature optimums of SC-T were at around pH 8.0 and 6 0 C , respectively, using Nα-p-tosyl-L-arginine methyl ester as a substrate. The SC-T was unstable below pH 5.0 and above 4 0 C , and it was stabilized by calcium ion. These enzymatic characteristics of SC-T were the same as those of other fish trypsins, especially spotted mackerel (S. borealis) trypsin, purified from viscera defatted by acetone. Therefore, we concluded that the SCO2 defatting process is useful as a substitute for organic solvent defatting process.