The optical-rotatory dispersion of myosin A

摘要: Effects of dioxane and p-chloromercuribenzoate (PCMB) on the optical-rotatory dispersion myosin A were measured in 0.6 M KCl at pH 7.0 compared with those ATPase activity. The α-helical content estimated from b0 term Moffitt-Yang plot was 57–61%. On addind 8–10 volume percent dioxane, increase helical by several pronounced activation firstly observed followed gradual decreases 2 h after addition decreased only a few percent, while activity disappeared completely. Immediately specific rotatory power 5000 showed its maximum about 10% accordance ATPase. alkaline-inactivated A, however, remained constant dioxane. adding PP1 before various times shift caused depressed completely during measurements. 3–4 moles PCMB per 105 g velocity Michaelis 20° increased, respectively, 0.22 to 0.44 mmoles P1/min/g 1.3 1.5·104M, temperature dependence increased significantly, 8 inhibited. 4 g. presence ATP or PP1, fell between either two. basis these other observations, it suggested that conformation active site is very susceptible influences that, accordingly, minute change induces