Isolation of ATPase accelerating peptides from fur seal muscle hydrolysate

In the previous paper, the ATPase accelerating peptides were found to be distinct from the vasoactive and vasodilatory peptides in the same hydrolysate. This work was undertaken to isolate the ATPase accelerating peptide from the fur seal muscle hydrolysate. Minced skeletal muscle of fur seal was digested with protease and the resulting hydrolysate was fractionated with 90%ethanol. The obtained precipitate and the effective agent was fund only in the precipitate. By continuous flow electrophoresis, the was divided into five major fractions, each of which was examind for accelerating effect on ATPase by two different methods, i.e., inorganic phosphate determination and pH-stat method. Among the five electrophoretic fractions, the second fraction E2 migrating to the anode showed the best accelerating effect, while the other fractions were less accelerative. Also the possible of Ca ions was refuted. E2 was also examined for physiological activity by kymographic recording of the contraction of rat intestine smooth muscle and showed an effect which is revealed by a contraction preceded by a slight relaxation. Thin layer chromatography revealed that there are more than two peptide components in fraction E2.