Kohama K, Oosawa M, Ito T, Maruyama K
Department of Pharmacology, Faculty of Medicine, University of Tokyo.
J Biochem. 1988 Dec;104(6):995-8. doi: 10.1093/oxfordjournals.jbchem.a122598.
Actin-modulating activity was analysed with the 16,131-dalton calcium-binding light chain (CaLc, Kobayashi et al. (1988) J. Biol. Chem. 263, 305-313) of Physarum myosin, which is under an inhibitory Ca-control (Kohama and Kendrick-Jones (1986) J. Biochem. 99, 1433-1446). When skeletal muscle actin was polymerized in the presence of CaLc and Ca2+, increases in both viscosity and birefringence were reduced under high shear conditions. However, CaLc did not inhibit actin polymerization under no or low shearing forces, which was demonstrated by a variety of methods including fluorescence intensity measurements using pyrenyl actin. We propose that actin polymerized in the presence of CaLc and Ca2+ is easily fragmented under high shearing forces to produce the changes in viscosity and birefringence.
利用绒泡菌肌球蛋白的16,131道尔顿钙结合轻链（CaLc，小林等人，(1988)《生物化学杂志》263, 305 - 313）分析肌动蛋白调节活性，该轻链受钙抑制调控（小滨和肯德里克 - 琼斯，(1986)《生物化学杂志》99, 1433 - 1446）。当骨骼肌肌动蛋白在CaLc和Ca²⁺存在下聚合时，在高剪切条件下，粘度和双折射的增加均降低。然而，CaLc在无剪切力或低剪切力条件下并不抑制肌动蛋白聚合，这通过多种方法得以证明，包括使用芘基肌动蛋白的荧光强度测量。我们提出，在CaLc和Ca²⁺存在下聚合的肌动蛋白在高剪切力作用下容易断裂，从而导致粘度和双折射的变化。
