Schuber F, Pascal M, Travo P
Eur J Biochem. 1978 Feb 1;83(1):205-14. doi: 10.1111/j.1432-1033.1978.tb12085.x.
The interaction between the nicotinamide adenine dinucleotide binding domain of calf spleen NAD glycohydrolase and its ligands has been studied. The use of competitive inhibitors, structurally related to different portions of the NAD molecule (i.e. adenosine and nicotinamide moieties), revealed the considerable importance of the binding between the pyrophosphate linkage and probably an arginyl residue of the active site. This interaction allows the positioning of the substrate in a conformation which permits catalysis to occur. The binding between the 2'-hydroxyl of the adenosine moiety and a residue of the active site, which exists in NAD-linked dehydrogenases, is probably missing in the calf spleen NAD glycohydrolase, based on the inhibition by salicylates, 2'-deoxyadenosine 5'-monophosphate and the hydrolysis of the 2'-deoxyadenosine analogue of NAD. The NAD glycohydrolase could be completely inactivated by 2,3-butanedione, an arginyl-modifying reagent. The reaction followed pseudo-first-order kinetics and the modification was found to be reversible. Woodward's reagent K, a reagent for carboxyl residues, partially inactivated the enzyme, which resulted in a change of the NAD glycohydrolase kinetic parameters Km and V. The inactivation rate was complicated by a parallel decomposition of the reagent.
对小牛脾NAD糖水解酶的烟酰胺腺嘌呤二核苷酸结合结构域与其配体之间的相互作用进行了研究。使用与NAD分子不同部分（即腺苷和烟酰胺部分）结构相关的竞争性抑制剂，揭示了焦磷酸键与活性位点可能的精氨酰残基之间结合的重要性。这种相互作用使底物处于允许催化发生的构象中。基于水杨酸盐、2'-脱氧腺苷5'-单磷酸对其的抑制作用以及NAD的2'-脱氧腺苷类似物的水解，小牛脾NAD糖水解酶中可能不存在腺苷部分的2'-羟基与活性位点残基之间的结合，而这种结合存在于NAD连接的脱氢酶中。NAD糖水解酶可被精氨酰修饰试剂2,3-丁二酮完全失活。该反应遵循准一级动力学，且发现这种修饰是可逆的。羧基残基试剂伍德沃德试剂K使该酶部分失活，这导致NAD糖水解酶动力学参数Km和V发生变化。试剂的平行分解使失活速率变得复杂。
