Aldehyde dismutase activity

TBADH also exhibits the so-called aldehyde dismutase activity 41. In contrast to HLADH, stochiometric dismutation of acetaldehyde into one equivalent of ethanol and acetic acid has been reported. A gem-diol mechanism was proposed for this reaction (Fig. 16.4-3). 

LADH catalyzes the dismutation of different aldehydes to alcohol and acid in the presence of NAD+ at high aldehyde concentrations (53,347,348). Dalziel and Dickinson (349) found that this reaction did not influence the kinetic parameters of normal aldehyde reduction, provided reasonable substrate concentrations were used. They also suggested a mechanism for the dismutase reaction based on a catalytic role of NAD+. Using acetyl pyridine AD+ instead of NAD+ it could, however, be demonstrated (350) that a net reduction of coenzyme occurs during this reaction. Later studies (351) have shown a stoichiometry of one mole NAD+ reduced per mole acid formed. It was also shown that with octanal as a substrate the reaction exhibits a much higher maximal velocity than with acetaldehyde. The isomerase activity of LADH previously reported (260,352) was later shown to result from impurities in the LADH preparations (353). 

Our study explored the oxidative damage due to overdosed iodine. Seven-week-old Wistar rats with normal iodine basehne were fed on water of normal, three-fold, and six-fold iodine levels for 24 weeks. Glutathione peroxidase (GSH-PX), superoxide dismutase (SOD), malondi-aldehyde (MDA) and H2O2 in the thyroid were detected. Either three-fold or six-fold high iodine supplementation decreased the activity of GSH-PX in thyroid, but did... 

Scheme 4. Schiff-base superoxide dismutase models surriving biological chelators. Upper section Dibenzoy Imethane does not readily react with 2-(2-aminoethyl)-pyridine due to a keto-enol tautomery. Therefore only poorly active and instable complexes are obtained. In contrast, 2-pyridine-aldehyde and putrescine yield a highly active and stable copper

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