Talbot J A, Hodges R S
J Biol Chem. 1979 May 25;254(10):3720-3.
A 20-residue peptide analog of the actomyosin ATPase inhibitory region of rabbit skeletal troponin I (Tn-I) has been synthesized by the solid phase method. The analog exhibited biological activity similar to both Tn-I and a 21-residue cyanogen bromide fragment of Tn-I. At ionic strengths where the inhibition of the actomyosin ATPase due to tropomyosin alone is low, the synthetic peptide in the presence of tropomyosin inhibits 90% of the original ATPase activity. In the absence of tropomyosin, the inhibition due to the peptide is much reduced. In contrast, salmine, a basic protein also known to inhibit the actomyosin ATPase, shows less inhibition in the presence of tropomyosin than it does in its absence. Gel electrophoresis data showed that the enhancement of the analog's inhibition by tropomyosin may be related to the analog's promotion of tropomyosin binding to F-actin similar to that reported for Tn-I and that the reduction of salmine inhibition by tropomyosin may be due to the binding of salmine by tropomyosin. At ionic strengths where binding and inhibition of tropomyosin is significant, the analog enhanced inhibition in a manner similar to that reported for whole Tn-I.
已通过固相法合成了兔骨骼肌肌钙蛋白I（Tn-I）的肌动球蛋白ATP酶抑制区域的一种20个残基的肽类似物。该类似物表现出与Tn-I以及Tn-I的一个21个残基的溴化氰片段相似的生物活性。在仅原肌球蛋白对肌动球蛋白ATP酶的抑制作用较低的离子强度下，在原肌球蛋白存在时，合成肽可抑制90%的原始ATP酶活性。在没有原肌球蛋白的情况下，该肽引起的抑制作用大大降低。相比之下，同样已知可抑制肌动球蛋白ATP酶的碱性蛋白鲑精蛋白，在有原肌球蛋白存在时的抑制作用比没有时小。凝胶电泳数据表明，原肌球蛋白对该类似物抑制作用的增强可能与该类似物促进原肌球蛋白与F-肌动蛋白结合有关，这与报道的Tn-I的情况相似，而原肌球蛋白对鲑精蛋白抑制作用的降低可能是由于原肌球蛋白与鲑精蛋白结合所致。在原肌球蛋白的结合和抑制作用显著的离子强度下，该类似物以与报道的完整Tn-I相似的方式增强抑制作用。
