Bunik V I, Buneeva O A, Gomazkova V S
Department of Biochemistry, Moscow State University, USSR.
Biochem Int. 1990 Aug;21(5):873-81.
The influence of reducing the KGD non-cooperative form by DTT on the KG binding by the enzyme was investigated. The chemical modification of KGD by DEP has revealed that reduction of KGD cysteine residues results in the appearance of the interaction of the dimer active sites upon the enzyme-substrate complex formation. The reduction of 2 SH-groups per KGD subunit: the most reactive one and a buried one--was established to be sufficient for the appearance of KGD cooperative properties in substrate binding as well as for the change in the enzyme activity plots versus substrate concentration. It is suggested that KGD can be regulated by thiol-disulfide exchange in the cell.
研究了二硫苏糖醇（DTT）减少KGD非合作形式对该酶结合KG的影响。DEP对KGD的化学修饰表明，KGD半胱氨酸残基的还原导致在酶-底物复合物形成时二聚体活性位点相互作用的出现。已确定每个KGD亚基还原2个SH基团（一个反应性最强的和一个埋藏的）足以使KGD在底物结合中出现协同特性，以及使酶活性与底物浓度的关系图发生变化。有人提出，KGD可在细胞中通过硫醇-二硫键交换进行调节。
