Rafter G W, Blair J B
Biochim Biophys Acta. 1987 Jun 17;913(2):195-9. doi: 10.1016/0167-4838(87)90330-x.
Homogeneous liver pyruvate kinase was reacted with different sulfhydryl reagents, which included o-iodosobenzoate, 5',5'-dithiobis(2-nitrobenzoic acid) and N-ethylmaleimide. Activity determinations of the treated enzyme made with and without Fru(1,6)P2 indicate that the protein contains two sulfhydryl groups per subunit important to its properties, one more accessible than the other. Fru(1,6)P2 added to mixtures prevented loss of activity obtained with o-iodosobenzoate and 5',5'-dithiobis(2-nitrobenzoic acid). It appears that Fru(1,6)P2 does not interfere with the reaction of the reagent with the sulfhydryl group, but prevents an ensuing conformational change, which leads to changes in the enzyme's properties.
将均一的肝脏丙酮酸激酶与不同的巯基试剂反应，这些试剂包括邻碘代苯甲酸、5',5'-二硫代双（2-硝基苯甲酸）和N-乙基马来酰亚胺。在有和没有 Fru(1,6)P2 的情况下对处理后的酶进行活性测定，结果表明该蛋白质每个亚基含有两个对其性质重要的巯基，其中一个比另一个更容易接近。添加到混合物中的 Fru(1,6)P2 可防止用邻碘代苯甲酸和 5',5'-二硫代双（2-硝基苯甲酸）处理后活性的丧失。似乎 Fru(1,6)P2 不会干扰试剂与巯基的反应，但可防止随后的构象变化，而这种构象变化会导致酶性质的改变。
