Ni(Ⅱ)与紫外线照射血清白蛋白的后续效应

Hysteretic Effect on Ni(Ⅱ)-Serum Albumin Under UV C Irradiation by UV-Vis Spectroscopy

用紫外光(253.7 nm)辐照1×10-4m o l.L-1的人血清白蛋白(HSA)和牛血清白蛋白(BSA),时间分别为0、1、2、3、4 h后,用同样浓度的N i(Ⅱ)溶液与辐照后的HSA和BSA作用,随时间扫描测定N i(Ⅱ)溶液与HSA和BSA的紫外可见光谱,发现N i(Ⅱ)溶液与照射过的或未经照射的HSA和BSA作用都具有明显的后续效应,而热力学常数k值随照射时间的延长逐渐降低,△G≠值却逐渐增大,这表明紫外光照射使蛋白质变性,导致N i(Ⅱ)与血清白蛋白的结合减弱,但结合的过程并未发生变化。

Using UV-Vis spectroscopy, a notable hysteretic effect was observed in the interaction of Ni^2＋ ion with human or bovine serum albumin irradiated under UV C（253.7 nm） at different time （0, 1, 2, 3 and 4 h）. The results showed that the processes of binding of Ni2＋ ion in different system were similar. However, k decreased and activation parameters △G^≠ increased when HSA and BSA were exposed to UV C longer. It can be inferred that binding ability of Ni^2＋ ion with human or bovine serum albumin weakened because UV C can make protein denatured.