Identification of Myofibril-bound Serine Protease from Red Seabream (Pagrus major) Ordinary Muscle

マダイ筋原線維結合型セリンプロテアーゼの同定

Identification of Myofibril-bound Serine Protease from Red Seabream (Pagrus major) Ordinary Muscle

Creators Ohkubo Makoto

Creators Yaguchi Shigenori

Creators Kondo Masakazu

Creators Maeda Toshimichi

Myofibrillar proteins were prepared from red seabream (Pagrus major) ordinary muscle by washing four times to remove sarcoplasmic proteins. Myosin heavy chain (MHC) of the myofibrillar proteins was degraded at 55℃ without the addition of any protease, and the degree of MHC degradation in red seabream was obviously low in comparison with brushtooth lizardfish (Saurida sp.). Specific activity of the red seabream myofibrillar proteins was approximately one‒thirtieth that of brushtooth lizardfish. Red seabream myofibril‒bound serine protease (MBSP) was solubilized by heat treatment of the washed myofibrillar proteins at 55℃ for 10 min. Hydrolysis of synthetic fluorogenic substrate by both the myofibril‒bound and solubilized MBSPs was inhibited by Pefabloc SC, a serine protease inhibitor. Both MBSPs rapidly hydrolyzed synthetic fluorogenic substrates containing arginine residues at the P_1 position. These results indicate that red seabream MBSP is a trypsin‒type serine protease, as reported in other fish species, such as white croaker (Pennahia argentata) and brushtooth lizardfish, utilized as ingredients of kamaboko.

[ISSN]0370-9361