致死条件が魚肉蛋白におよぼす影響-III : ミオシン区蛋白の粘度にみられる相異

概要

論文の詳細を見る
Previously it was suggested from salting-out analysis that intermolecular interaction between actin and myosin might be weaker in myosins (=muscle proteins which are extractable with 0.6 M KCl and precipitate on dilution) from carp killed after struggle than in those from carp put to an instant death. Variation in mutual reactivity of actin and myosin would necessarily have any influence on shape of myosins particles. Thus in the present work, viscosity was examined, expecting to obtain some knowledge about the variation in particle shape of fish myosins as a reflection of difference in lethal conditions. Material and Method As test animals carp, red sea bream, and flatfish (for scientific names, see Table 2) were used. With each species, two methods of killing fish have been compared in respect of their effect on the viscosity behavior of extracted myosins: a group of fish was put to an instant death by beheading, and the other was allowed for several hours in air and then beheaded. Red sea bream died 30min. after it was taken from water. Viscosity was measured under varying concentrations (c) and mean velocity gradients ( ?? ), and ηsp/c (ηsp: specific viscosity) were plotted against ?? +kc, k being an arbitary constant and here put to 1000. From viscosity patterns thus obtained (Figs. 1-3), intrinsic viscosity [η]=(ηsp/c)c→0 ?? →0 was determined and relations between ηsp/c and ?? as well as between ηsp/c and c were examined for each sample. In viscosity patterns (Figs. 1-3), slopes of lines parallel to XZ denote velocity gradient dependence of ηsp/c at respective concentrations, and slopes of lines parallel to XY denote concentration dependence at respective velocity gradients. Results 1. As seen in Table 1, values of [η] fell roughly between 2 and 3 for all tested species of fish. No significant difference in [η] was observed between instant death group and deathafter-struggle group with the same species. Therefore, the same would be true with avarage particle asymmetry in resting solution at infinite dilution. 2. Velocity gradient dependence of ηsp/c which is a function of both asymmetry and length of particle, was obviously greater in instant death group than in the other with each species, as seen from slopes of XZ curves in Figs. 1-3. This might lead to conclusion that whether myosins particles are rigid or not, average length of molecules of myosins should be greater in instant death group, at least in the field of flow. 3. Effect of concentration upon ηsp/c varied considerably with species of fish, as seen from slopes of XY curves in Figs. 1-3. The effect was marked in carp (Fig. 1) and flatfish (Fig. 3), being slightly greater in the former. Difference was hardly observed with these fishes between instant death and death-after-struggle groups. In these respects red sea bream (Fig. 2) proved to be unique. Thus, in instant death group, concentration effect was so small as ηsp/c seemed nearly constant independent of c. In death-after-struggle group the effect of concentration was appreciable, but obviously smaller compared with that in carp or flatfish. As concentration effect is considered due to mutual interference of solute particles, the effect might be a function of accessible active groups on the particles as well as asymmetry and length of solute particles.
公益社団法人日本水産学会の論文

致死条件が魚肉蛋白におよぼす影響-III : ミオシン区蛋白の粘度にみられる相異

スポンサーリンク

概要

著者

関連論文

スポンサーリンク