摘要
合成了主体化合物N-(对二甲氨基苯甲酰胺)-N′-苯基脲(1),采用荧光光谱法研究1与血清白蛋白间的相互作用。在pH7.40的Tris-HCl缓冲溶液中,主体1的荧光强度在一定范围内随牛血清白蛋白(BSA)或人血清白蛋白(HSA)的加入呈线性增强。同时主体1可猝灭血清白蛋白的内源荧光,猝灭过程源于共振能量转移,并计算了主体1和血清白蛋白间的结合常数,分别为4169 mol-1L(BSA)和1412 mol-1L(HSA),结合位点数均近似为1。此外,同步荧光光谱的变化表明主体1与白蛋白作用时更接近其中的酪氨酸残基但未改变其构象。同时还研究了与1具有相似结构的N-(对二甲氨基苯甲酰胺)-N′-苯基硫脲(2)与血清白蛋白的相互作用,结果显示两者之间无明显的相互作用。蛋白质对两者光谱响应的差异可能是因为1具有两个类似于肽键的酰胺键,与蛋白质形成氢键,故与蛋白质的作用较强。
A new compound, 1 - [ p - （ dimethylamino ） benzoyl ] - 4 - phenyl - semicarbazide （ 1 ）, had been synthesized and the interactions between 1 and bovine serum albumin （BSA） or human serum albumin （HSA） were studied by fluorescence spectroscopy. The results suggested that the fluorescence intensity of 1 increased and showed good linear relationship with the amount of BSA or HSA. 1 could also quench the intrinsic fluorescence of serum albumin through static quenching procedure. The binding constants （Kb） between 1 and proteins were 4169 mol^-1 L for BSA and 1 412 mol^- 1 L for HSA respectively, meanwhile the average number of binding sites （n） was about 1. The binding distance between 1 and BSA or HSA was evaluated on the basis of the theory of energy transfer, which indicated that BSA could transfer energy to 1 more easily, compared with HSA. In addition, the effect of 1 on the conformation of BSA/HSA was investigated by synchronous fluorescence spectroscopy which implied that 1 was close to tyrosine residue but didn＇ t effect the conformation of protein. At the same time, the interaction between the control compound [ 1 - [ p - （dimethylamino） benzoyl ] - 4 - phenyl - thiosemicar bazide （ 2 ） ] and proteins was also investigated. The results showed neither fluorescence spectral profile nor fluorescence intensity changes of 2 were observable in the presence of HSA or BSA. Thus, it was assumed that 1 possessed strong binding ability with protein due to the amide bond of urea group which is similar to the peptide bond. The results provide the useful data for drug design and screening.
出处
《南昌大学学报（理科版）》
CAS
北大核心
2009年第5期456-459,464,共5页
Journal of Nanchang University(Natural Science)
基金
江西省自然科学基金资助项目(JXNSFNo2007GZH2119)
江西省教育厅资助项目(GJJ09040)
