Schröer E, Wegner A
Eur J Biochem. 1985 Dec 16;153(3):515-20. doi: 10.1111/j.1432-1033.1985.tb09332.x.
An actin-polymerization-inhibiting protein, that occurs in crude preparations of vinculin from chicken gizzard, has been purified by DEAE-cellulose and carboxymethyl ion-exchange chromatography. According to sodium dodecyl sulfate (SDS)/polyacrylamide gel electrophoresis and to gel filtration the polymerization-inhibiting protein is heterogeneous and the molecular mass ranges from 20 kDa to 80 kDa. After treatment with acid the polymerization-inhibiting activity was found to migrate on a SDS/polyacrylamide gel as a single band of molecular mass about 32 kDa. The mechanism of the action of the polymerization-inhibiting protein on actin assembly was investigated by the effect on the kinetics of actin polymerization. The polymerization-inhibiting protein blocks elongation of actin filaments at substoichiometric ratios but does not nucleate actin filaments. The equilibrium constant for binding of the polymerization-inhibiting protein to the barbed end of an actin filament was estimated to be 2 X 10(6) M-1 in 100 mM KCl and 2 mM MgCl2, and 35 X 10(6) M-1 in 2 mM MgCl2.
一种存在于鸡胗纽蛋白粗制品中的肌动蛋白聚合抑制蛋白，已通过DEAE - 纤维素和羧甲基离子交换色谱法进行了纯化。根据十二烷基硫酸钠（SDS）/聚丙烯酰胺凝胶电泳和凝胶过滤结果，该聚合抑制蛋白具有异质性，分子量范围为20 kDa至80 kDa。经酸处理后，发现聚合抑制活性在SDS/聚丙烯酰胺凝胶上迁移为一条分子量约为32 kDa的单带。通过研究其对肌动蛋白聚合动力学的影响，对聚合抑制蛋白作用于肌动蛋白组装的机制进行了研究。该聚合抑制蛋白以亚化学计量比阻断肌动蛋白丝的伸长，但不会引发肌动蛋白丝的成核。在100 mM KCl和2 mM MgCl2条件下，聚合抑制蛋白与肌动蛋白丝的带刺端结合的平衡常数估计为2×10⁶ M⁻¹，在2 mM MgCl2条件下为35×10⁶ M⁻¹。
