Ashmarina L I, Muronets V I, Nagradova N K
Biokhimiia. 1994 Jun;59(6):873-80.
The ability of glyceraldehyde-3-phosphate dehydrogenase (GAPD) to associate with 3-phosphoglycerate kinase (3-PGK) in human erythrocytes has been studied. It was found that a stable GAPD-3-PGK complex can be isolated from human erythrocyte hemolysates using immobilized monoclonal antibodies that are specific for GAPD. The complex does not dissociate at high ionic strength (up to 0.3 M NaCl) but is decomposed in the presence of specific ligands interacting with GAPD and 3-PGK, e.g., 1,3-diphosphoglycerate. The interaction between GAPD and 3-PGK isolated from human erythrocytes was investigated. To assess the binding parameters, immobilized GAPD and soluble 3-PGK from erythrocytes were used. About 2.3 moles of monomeric 3-PGK (Kd = 2.4 microM) were bound per mole of the immobilized tetramer of GAPD. Under these conditions the rabbit muscle enzymes form more weak (Kd = 3.8 microM), whereas the yeast enzyme--more stable complexes (Kd = 1.5 microM). No such complexes were detected when the enzyme pairs were isolated from phylogenetically distant sources, such as yeast and mammalian tissues. The species specificity of binding of the two enzymes and possible causes of formation of such stable complexes in erythrocyte lysate are discussed.
对人红细胞中甘油醛 - 3 - 磷酸脱氢酶（GAPD）与3 - 磷酸甘油酸激酶（3 - PGK）结合能力进行了研究。发现使用对GAPD具有特异性的固定化单克隆抗体，可从人红细胞溶血产物中分离出稳定的GAPD - 3 - PGK复合物。该复合物在高离子强度（高达0.3M NaCl）下不会解离，但在存在与GAPD和3 - PGK相互作用的特异性配体（例如1,3 - 二磷酸甘油酸）时会分解。研究了从人红细胞中分离出的GAPD和3 - PGK之间的相互作用。为评估结合参数，使用了固定化的GAPD和来自红细胞的可溶性3 - PGK。每摩尔固定化的GAPD四聚体结合约2.3摩尔单体3 - PGK（Kd = 2.4μM）。在这些条件下，兔肌肉酶形成较弱的复合物（Kd = 3.8μM），而酵母酶形成更稳定的复合物（Kd = 1.5μM）。当从系统发育上距离较远的来源（如酵母和哺乳动物组织）分离酶对时，未检测到此类复合物。讨论了两种酶结合的物种特异性以及红细胞裂解物中形成此类稳定复合物的可能原因。
