Enzymatic indicator reaction of immobilised oxidase and dehydrogenase - for substrate recycling, with immobilisation of co-factor and additional dehydrogenase for co-factor regeneration

摘要

Enzymatic indicator reaction uses immobilised oxidase (I) and dehydrogenase (II), in presence of NAD/NADH, with recycle of reaction prod. into starting material (enzyme substrate). The new features are that (1) the NAD/NADH is immobilised and (2) another immobilised dehydrogenase (IIa) is used for regeneration of the co-factor. Also new is an amperometric sensor for this reaction carrying (I), (II), NAD/NADH and (IIa), all in immmobilised form. (I) and (II) are immobilised on a membrane through which the aq. assay medium can flow. NAD/NADH is immobilised on a macromolecule, e.g. polyethylene glycol. USE/ADVANTAGE - Recycle of substrate amplifies the measurement signal but requires a large (stoichiometric) amt. of expensive co-factor. Incorporation of (IIa) and immobilisation of NAD allow the co-factor to be reused.