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利用定点突变技术构建并纯化了钙调神经磷酸酶Ａ亚基Ｌｏｏｐ７区及其附近的几个突变体，进行了磷酸酶比活性及溶液构象的研究，并通过它们与野生型的比较，研究ＣＮ和免疫抑制药物的相互作用．结果表明：删除Ｌｏｏｐ７中心区１个或几个氨基酸的突变体，其磷酸酶比活性均高于野生型，远紫外ＣＤ谱显示各突变体溶液构象均发生了改变．免疫抑制剂复合物ＣｓＡ－ＣｙＰ明显抑制野生型ＣＮ的酶活，而对Ｌｏｏｐ７区各突变体影响不大，说明Ｌｏｏｐ７区定点突变改变了ＣｓＡ－ＣｙＰ和ＣＮ之间的相互作用．对从传统中药中提取的成分进行检测发现，中药成分ＺＩＰ１能对ＣＮ野生型和突变体都起直接的抑制作用，而不需要体内结合物的存在．提示ＣＮ的Ｌｏｏｐ７区是ＣｓＡ－ＣｙＰ起抑制作用的关键部位，中药成分ＺＩＰ１对ＣＮ的抑制作用很值得深入研究。
The site-specific mutagenesis technique was used to construct and purify the Loop 7 and its mutants in the vicinity of A subunit of calcineurin. The specific activity of phosphatase and the conformation of the solution were studied. Compared with wild type, CN Interaction with immunosuppressive drugs. The results showed that the specific phosphatase activity of mutants with deletion of one or several amino acids in the central loop of Loop7 was higher than that of the wild type. The far-UV CD spectra showed that the conformation of each mutant was changed. The immunosuppressant complex CsA-CyP significantly inhibited the activity of wild-type CN, but had little effect on the mutants in Loop7, indicating that site-directed mutagenesis in Loop7 changed the interaction between CsA-CyP and CN. Examination of the components extracted from the traditional Chinese medicine found that ZIP1 can directly inhibit the CN wild type and the mutant without the need of the in vivo conjugate. It is suggested that the Loop 7 region of CN is a key part of the inhibitory effect of CsA-CyP. The suppressive effect of ZIP1 on CN is worth further study.