锌离子对氨基酰化酶构象及其稳定性的影响

天然氨基酰化酶和脱谷氨基酰化酶无论在二级结构（用ＣＤ和ＦＴＩＲ监测）还是三级结构上（以荧光发射光谱监测）都有明显的差异，表明了脱锌后酶的有序度降低；当比较天然和脱锌氨基酸化酶对去圬剂的稳定性时，结果表明脱锌后酶的构象的稳定性明显降低．因此可以认为锌离子对维持酶分子活性部位的特定构象以及构象的稳定性具有重要的作用．

EFFECT OF ZINC ION ON CONFORMATION AND ITS STABILITY OF AMINOACYLASE

ffect of Zn2 on the secondary sic of aminoacylase was studied by circulardichroism and deconvolved FTIR spectra. The result showed that after removal of Zn2 the contents of orded secondary structure of enzyme decrased. The fluorescence emission spectra,as compared to Holo-enzyme, showed that the emission maximum of Apo-enzyme had a red-shift from 335nm to 336.5mp indicating the occurrence of some unfolding of the tertiary structure of Apo-enzyme. The stability of Apo-against detergent decreased markedly.It suggests that the presence of Zn2 haps to keep the active site of aminoacylase stable in a specific conformation atate.