ATPase Activity And Thermally Induced Gelation Properties Of Myosin

Three parts were included in this paper:(l)Modified extraction and purification of myosin from rabbit skeletal muscle. (2)Adjusted the method of measurating activity of myosin ATPase, and studied the property of ATPase in different conditions such as pH, ionic strength and others. (3)Response surface of Design was used for studying the effect of pH, KC1 and polyphosphate to gel formation of myosin, responses of design were ionic strength, water holding capability(WHC), solubility and ATPase activity.(1)Modified extraction and purification of myosin from rabbit skeletal muscle, aimed at the condition of hypercentrifugation78000g 1h. By precipitiation of actomyosin and adjusting separate parameter, combining NH4(S04)2 sedimentation and may add a step that reprecipitiating raw protein before separating actomyosin. Compared with method of Naussl969, reducing time and workload, lessening cost.(2) Adjusted the method of measurating ATPase activity of myosin, also studied the ATPase properties affected by pH, ionic strength and storage time. The results showed that Ca2* could activate myosin-ATPase effectively, Ca2+-ATPase could reflect distinct change of myosin, Km value of Ca2+-activated myosin-ATPase at 0.1 I was 3.332 mM, Vmax was 0.676umol/mg.min, Ca2+-ATPase at pH5.5 amount to max, Ca2+-ATPase was sensitive to ionic strength, while Mg2+-ATPase was stable.(3)Response surface of Design was used for studying the effect of pH, KC1 and polyphosphate to gel formation of myosin, responses of design were ionic strength, water holding capability(WHC), solubility and ATPase activity. Functional parameters of Finer gelation entity was KC1 concentration at 0.38M, pH at 5.9 , however, phosphates exerted action in relation to levels of KC1 and muscle types. The experiment attributed the effect of phosphate correlating with pH, salt concentration and muscle types, which primarily increased pH , ionic strength and specific polyphosphate protein interaction; as to raw meat, the most important was insolubilizing protein and increasing the number of myosin, also included the action to dissociate actomyosin. WHC of heated induced gelation came in for the effect of pH, KC1 and phosphates, Functional parameters of WHC was at about pH 6.2, KC1 concentration 0.5 M in the range from 0.4 to 0.6, yet Phosphate played a complex rolecorrelating to fibre types that PM-myosin was determined by SPP and that SMp-myosin by SPP, TPP and HMP, precondition that the pH role of phosphate was involved in pH absolutely. No difference between PM-myosin and SMp-myosin to sulubility, behaving linearly increase along with the rise of pH value and KC1 concentration. ATPase activity was also donminated by KC1 and pH, amount to max at 0.4 level of KC1, which difference between PM-myosin and SMp-myosin was that ATPase activity of PM-myosin achieved max at pH6.2, and yet SMp-myosin at pH6.6.