COMPARATIVE STUDIES ON CHANGES OF ACTOMYOSIN IN CULTURED AND WILD PRAWNS BY THERMAL TREATMENT

The changes of actomy osin( AM) in cultured and wi ld praw ns by thermal tr eatment w ere studied biochemica lly and phy sica lly. The experimental result s showed that the so lubility and C a 2+ -ATPase a ct iv ities o f AM decr eased with the increase o f tempe rature, in w hich the cultured pr awn. s decreased mo re rapidly than tho se of the w ild. s. Ther e w as a sma ll dif ference in a ct iv ity between Mg2 -ATPase and Ca2 -ATPase . The ATPase of cultured praw n w as ent irely deactiv ated a t 50 e , w hile the w ild at 55 e . The number o f unmasked-SH gro ups g radually incr ease d f rom 20 to 40 e , then decreased. The hydropho bicit ies of AM incr eased signif ica nt ly w ith the elev at ion o f temperature abo ve 40 e . No change o f ATP sensit ivit ies at no rma l temperature, but decreased rapidly f rom 35 e . All the ment io ned indices in AM were great ly af fected in the temper ature r ang ing f rom 30 to 40 e , howeve r, AM o f cultured praw n w as less stable than the w ild o ne.