CAJ | 학술논문

外加毫摩尔浓度的重金属离子Hg2+,会引起BSA或HSA的色氨酸荧光下降,并且35℃时的变化比25℃时更明显,HSA的变化比BSA的大.Stern Volmer作图分析结果表明荧光淬灭主要是由动态淬灭引起的.用NBS对BSA和HSA的色氨酸残基进行特异性修饰后,Hg2+只引起NBS修饰的HSA的酪氨酸荧光轻微降低,但对NBS修饰的BSA的酪氨酸荧光几乎没有影响.远紫外和近紫外CD谱分析表明:Hg2+的结合要引起BSA,HSA以及NBS修饰的HSA二级结构的α螺旋减少,三级结构发生一定的改变.这些结果表明BSA和HSA中色氨酸附近的二硫桥可能是Hg2+的作用部位.
외가호마이농도적중금속리자Hg2+,회인기BSA혹HSA적색안산형광하강,병차35℃시적변화비25℃시경명현,HSA적변화비BSA적대.Stern Volmer작도분석결과표명형광쉬멸주요시유동태쉬멸인기적.용NBS대BSA화HSA적색안산잔기진행특이성수식후,Hg2+지인기NBS수식적HSA적락안산형광경미강저,단대NBS수식적BSA적락안산형광궤호몰유영향.원자외화근자외CD보분석표명:Hg2+적결합요인기BSA,HSA이급NBS수식적HSA이급결구적α라선감소,삼급결구발생일정적개변.저사결과표명BSA화HSA중색안산부근적이류교가능시Hg2+적작용부위.
Hg (Ⅱ) induces quenching of trytophan fluorescence of BSA and HSA, and the quenching of HSA is more intense; the change of fluorescence intensity at 35℃ is more dramatic than that at 25C. Stern Volmer plots indicate the occurrence of dynamic quenching. Hg (Ⅱ) can only induce slight decrease of tyrosine fluorescence of NBS modified HSA, but has no effect on that of modified BSA. Far-UV and near-UV CD spectra provide evidence that the binding of Hg (Ⅱ) induces BSA, HSA and NBS modified HSA a loss of α-helix and rearrangement of tertiary structure. These results suggest that the binding sits of Hg (Ⅱ) is the disulfide bridges in the proximity of the tryptophan residues in BSA and HSA.