Prediction of affinities of peptides for calmodulin

A simple method has been developed to predict the calmodulin-binding domains of peptides and the affinities of the peptides for calmodulin based on a model for the calmodulin-binding domains of peptides proposed in a previous paper and the literature data of calmodulin-binding peptides. The effects of hydrophobitities, α-helix-forming tendencies, and basicities of peptides on their affinities for calmodulin were studied. Model peptides were designed to examine the calmodulin-binding domain model and the prediction method. The determined dissociation constants of the complexes formed from the model peptides and calmodulin are in good agreement with the predicted results.     

光谱法研究钙调素与蜂毒肽片断及其类似物的相互作用

设计合成了蜂毒肽片断及其类似物:Mel15,Mel15(8F)和Mel15(7P),这些多肽与钙调素有很强的结合力,而且链段很短,因此它们可作为钙调素可结合蛋白质的结合部位的模型.本文采用光谱法研究了它们与钙调素的相互作用.荧光发射光谱法结果表明,多肽Mel15在与钙调素相互作用时,肽链中的Trp基团的微环境变得更加疏水,说明Mel15中的Trp残基可能与钙调素的疏水性表面靠近.紫外差谱测试表明,只有当钙调素分子结合2个Ca~(2+)后,才可以与多肽Mel15(8F)结合.圆二色谱法研究表明,多肽与钙调素结合后多肽分子和钙调素分子的α-螺旋结构的含量都被诱导而增加,结合力越大,则越多的残基被诱导形成α-螺旋结构.