Aizawa M, Coughlin R W, Charles M
Biotechnol Bioeng. 1976 Feb;18(2):209-15. doi: 10.1002/bit.260180207.
A covalently bound adduct of nicotinamide adenine dinucleotide (NAD) with alginic acid has been found to be enzymatically active and to undergo electrochemical oxidation or reduction without significant loss of its enzymatic activity. The preparation of the adduct itself (from NAD+, alginic acid, and 1-cyclohexyl-3-(2-morpholinoethyl)-carbodiimide metho-p-toluenesulfonate) is also accomplished with substantially complete retention of enzymatic activity. This adduct has been converted from the oxidized to the reduced form by controlled potential electrolysis using mercury and stainless-steel electrodes. This electrolytically produced NADH complex could be oxidized again to the enzymatically active NAD+ complex by enzymatic reaction with the proton acceptor, 2,6-dichlorophenol indophenol, as catalyzed by diaphorase. Using this electrolytic method with immobilized NAD, it is now possible to carry out redox reactions in which NADH is enzymatically oxidized to NAD+, with the simultaneous electrolytic regeneration of the reduced form, NADH, from the oxidized form, NAD+, produced in the enzymatic reaction.
已发现烟酰胺腺嘌呤二核苷酸（NAD）与海藻酸的共价结合加合物具有酶活性，并且在进行电化学氧化或还原时其酶活性不会显著丧失。加合物本身的制备（由NAD⁺、海藻酸和1-环己基-3-(2-吗啉代乙基)-碳二亚胺对甲苯磺酸盐制备）也能在酶活性基本完全保留的情况下完成。通过使用汞电极和不锈钢电极进行控制电位电解，该加合物已从氧化形式转化为还原形式。这种电解产生的NADH复合物可以通过在心肌黄酶催化下与质子受体2,6-二氯酚靛酚发生酶促反应，再次氧化为具有酶活性的NAD⁺复合物。使用这种固定化NAD的电解方法，现在可以进行氧化还原反应，其中NADH被酶促氧化为NAD⁺
