铬离子与酪氨酸作用的光谱研究

Spectral Study on the Interaction of Tyrosine with Chromium(Ⅲ)

在pH5.6的0.1mol/LN-2-羟乙基哌嗪-N′-2-乙磺酸(Hepes)及室温条件下,用荧光光度计进行了Cr3+对酪氨酸(Tyr)的滴定。结果表明Cr(Ⅲ)与Tyr形成1:1的配合物。再用不同比例的[EDTA]/[Cr3+]系列溶液分别滴定Tyr,由EDTA与Tyr的竞争结合,间接求得Cr(Ⅲ)与Tyr的结合常数lgKCr-Tyr=16.49±0.14。

In the presence of 0.1mol/L N-2-hydroxyethylpiperazine-N-2-ethanesulfonic acid（Hepes）（pH=5.6） at room temperature,the titration of tyrosine with chromium（Ⅲ） was carried out by fluorescence photometer.Chromium（Ⅲ） and tyrosine can form a 1：1 complex.The respective titration of tyrosine with different ratio of series[EDTA]/[Cr3＋] solution was investigated.From the competition between EDTA and tyrosine for chromium（Ⅲ）,the binding constant of chromium（Ⅲ） to tyrosine was measured to be lgKCr-Tyr=16.49±0.14.