Voskoboev A I, Grinevich V P
Biokhimiia. 1978 Oct;43(10):1743-8.
The content of free sulfhydril groups in yeast thiamine pyrophosphokinase (EC 2.7.6.2) was studied. Their blocking was found not to affect considerably the enzyme activity. N-bromsuccinimide developes the inhibitory effect only if taken in excessive concentrations, which indicates that tryptophane has no key position for the enzyme-substrate complex formation. On account of high speed of photoinactivation with Rose bengale and methilene blue, sigmoid dependence of activity loss on pH under irradiation, characteristic narrowing of the modified enzyme absorption spectrum, it is suggested that imidazole residue of the histidine is one of the functional groups of thiamine pyrophosphokinase.
对酵母硫胺素焦磷酸激酶（EC 2.7.6.2）中游离巯基的含量进行了研究。发现它们的封闭对酶活性没有显著影响。N-溴代琥珀酰亚胺只有在浓度过高时才会产生抑制作用，这表明色氨酸对于酶-底物复合物的形成没有关键作用。鉴于用孟加拉玫瑰红和亚甲蓝进行光灭活的速度很快，辐照下活性损失对pH呈S形依赖性，修饰酶吸收光谱的特征性变窄，有人提出组氨酸的咪唑残基是硫胺素焦磷酸激酶的功能基团之一。
