Formate dehydrogenase compounds

In order to broaden the field of biocatalysis in ionic liquids, other enzyme classes have also been screened. Of special interest are oxidoreductases for the enan-tioselective reduction of prochiral ketones [40]. Formate dehydrogenase from Candida boidinii was found to be stable and active in mixtures of [MMIM][MeS04] with buffer (Entry 12) [41]. So far, however, we have not been able to find an alcohol dehydrogenase that is active in the presence of ionic liquids in order to make use of another advantage of ionic liquids that they increase the solubility of hydrophobic compounds in aqueous systems. On addition of 40 % v/v of [MMIM][MeS04] to water, for example, the solubility of acetophenone is increased from 20 mmol to 200 mmol L ... 

Ernst, M., Kaup, B., Mueller, M. et al. (2005) Enantioselective reduction of carbonyl compounds by whole-cell biotransformation, combining a formate dehydrogenase and a (R)-specihc alcohol dehydrogenase. Applied Microbiology and Biotechnology, 66 (6), 629-634. 

A very interesting aspect of biological selenium compounds is the occurrence of selenocysteine in a protein component (selenoprotein A) of glycine reductase, in formate dehydrogenase and in glutathione peroxidase (see below). As pointed out by Stadt-man , the incorporation of this rather unusual amino acid into proteins in a very specific way poses something of a mystery and at present the mechanism by which this occurs is not known. 

Asymmetric reduction of carbonyl compounds and production of isotopically labelled species has been achieved. A system based on deuterated formate and formate dehydrogenase provides the best system for the introduction of deuterium through nicotinamide-cofactor catalysed process (Table 2). 

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