Kovár J, Klukanová H
Biochim Biophys Acta. 1984 Jul 17;788(1):98-109. doi: 10.1016/0167-4838(84)90301-7.
Interaction of the electrolytically prepared dimers of nicotinamide adenine nucleotide, (NAD)2, and nicotinamide adenine nucleotide phosphate, (NADP)2, with lactate, alcohol, glyceraldehyde 3-phosphate, alpha-glycerophosphate, glutamate and glucose-6-phosphate dehydrogenase has been studied using the quenching of protein fluorescence, kinetics of inhibition and the stopped-flow method. It has been shown that these enzymes are able to bind dimers preserving their coenzyme specificity. The most efficient binding of (NAD)2 has been observed in the case of glutamate and lactate (bovine heart) dehydrogenase, the dissociation constants being 6 and 8 microM, respectively. (NADP)2 affinity to glutamate and glucose-6-phosphate dehydrogenase is also fairly high. More detailed studies on the interactions of dimers with alcohol and glutamate dehydrogenase have shown that the binding to the coenzyme binding site is the prerequisite for the association. However, some additional stabilizing interactions with other enzyme groups are not excluded, though (NAD)2 does not bind to the known binding sites of these enzymes, such as the substrate pocket of alcohol dehydrogenase and the regulatory binding sites for ADP and GTP of glutamate dehydrogenase.
已使用蛋白质荧光猝灭、抑制动力学和停流法研究了电解制备的烟酰胺腺嘌呤二核苷酸二聚体（NAD）₂和烟酰胺腺嘌呤磷酸二核苷酸二聚体（NADP）₂与乳酸、乙醇、3-磷酸甘油醛、α-甘油磷酸、谷氨酸和葡萄糖-6-磷酸脱氢酶的相互作用。结果表明，这些酶能够结合二聚体并保持其辅酶特异性。在谷氨酸和乳酸（牛心）脱氢酶的情况下，观察到（NAD）₂的结合效率最高，解离常数分别为6和8 μM。（NADP）₂对谷氨酸和葡萄糖-6-磷酸脱氢酶的亲和力也相当高。对二聚体与乙醇和谷氨酸脱氢酶相互作用的更详细研究表明，与辅酶结合位点的结合是缔合的前提条件。然而，尽管（NAD）₂不与这些酶的已知结合位点结合，如乙醇脱氢酶的底物口袋以及谷氨酸脱氢酶的ADP和GTP调节结合位点，但不排除与其他酶基团存在一些额外的稳定相互作用。
