キハダマグロジェリ-ミ-トからのジェリ-化原因プロテア-ゼの分離〔マグロ類ジェリ-ミ-トに関する研究-5-〕

概要

論文の詳細を見る
Proteases in the jellied meat of yellowfin tuna Thunnus albacores were separated into three fractions, designated J-I, J-II-1 and J-II-2, by a method which consists of ion-exchange chromatography and gel-filtration. Fraction J-II-2 was found to correspond to cathepsin D, which is normally present in the muscle. The protease activity of fraction J-II-1 was negligible, whereas that of J-I, a thiol protease, was much higher. It was demonstrated that J-I jellified the freeze-dried normal yellowfin tune meat at 25°C and pH 5.8, while cathepsin D did not jellify the meat at all under the same conditions. Neither J-I protease activity nor any spores of a sporozoa Hexacapsula neothunni were detected in the dark meat which was not jellified. These findings suggest that J-I protease, possibly secreted from the sporozoan parasite, is mainly responsible for the jellification of yellowfin tuna meat.