ACANTHAMOEBA PROFILIN INTERACTS WITH G-ACTIN TO INCREASE THE RATE OF EXCHANGE OF ACTIN-BOUND ADENOSINE 5'-TRIPHOSPHATE
ACANTHAMOEBA PROFILIN INTERACTS WITH G-ACTIN TO INCREASE THE RATE OF EXCHANGE OF ACTIN-BOUND ADENOSINE 5'-TRIPHOSPHATE
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DOI：
10.1021/bi00564a033
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发表时间：
1980-01-01
期刊：
影响因子：
2.9
通讯作者：
KORN, ED
中科院分区：
文献类型：
--
作者：
MOCKRIN, SC;KORN, ED
棘阿米巴Profilin是一种12,000道尔顿的蛋白质，可抑制肌动蛋白聚合，摩尔过量7倍，可使结合在G-肌动蛋白上的ATP与溶液中的ATP交换速率增加约17倍，即从7.7倍增加到7.7倍。10-4到1.3倍。10-2 S-1，25度。C，0.033 mM钙离子和0.1mM三磷酸腺苷，pH 7.5。对平衡同位素交换数据的详细分析表明，Profilin和肌动蛋白形成1：1的络合物，Kd=4.7倍。10-5M，Profilin与肌动蛋白的结合是快速和可逆的。肌动蛋白-Profilin复合体与1摩尔的ATP/摩尔结合，G-肌动蛋白也如此。Profilin不与三磷酸腺苷或钙离子相互作用。
A 7-fold molar excess of Acanthamoeba profilin, a 12,000-dalton protein that inhibits actin polymerization, increases the rate of exchange of ATP bound to G-actin with ATP in solution about 17-fold, i.e., from 7.7 .times. 10-4 to 1.3 .times. 10-2 s-1, at 25.degree. C, 0.033 mM Ca2+ and 0.1 mM ATP, pH 7.5. Detailed analysis of the equilibrium isotope-exchange data shows that profilin and actin form a 1:1 complex with KD = 4.7 .times. 10-5 M and that the binding of profilin to actin is rapid and reversible. The actin-profilin complex binds 1 mol of ATP/mol, as does G-actin. Profilin does not interact with ATP or Ca2+.