A simple spectrophotometric method for estimation of diamine oxidase (DAO) activity was developed, based on a coupled reaction with NADH-dependent alcohol-dehydrogenase. Cystamine, upon DA0 action, is transformed into an aminoaldehyde which reacts quickly and quantitatively with NADH in the presenc
An NADH coupled assay system for galactose oxidase
✍ Scribed by Gad Avigad
- Publisher
- Elsevier Science
- Year
- 1978
- Tongue
- English
- Weight
- 434 KB
- Volume
- 86
- Category
- Article
- ISSN
- 0003-2697
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✦ Synopsis
A galactose oxidase (EC 1.1.3.9):NADH-peroxidase (EC 1.11.1.1) coupled assay system is used for the estimation of galactose oxidase activity. Spectrophotometric measurement of NADH consumption yields direct quantitative value of enzymic activity or can be used for the end-point determination of the amount of galactose oxidase substrate present in test solutions. Use of similar coupled systems is suggested for the assay of other H,O,-producing enzymes and their substrates.
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## Abstract The active site of the enzyme galactose oxidase (GOase) contains square‐pyramidal monocopper site, one of whose ligands is a tyrosinate side‐chain that is oxidized to an unusually stable radical in the active enzyme. The structure of this non‐innocent tyrosinate is unique in two ways. F