RESUMO
NAD-dependent formate dehydrogenase was purified from a cell-free extract of methanol-consuming yeast Candida methylica, using chromatography on DEAE-cellulose and gel-filtration on Sephadex G-200. The enzyme is electrophoretically homogeneous, consists of two identical subunits with molecular weight of 46,000 and is active within the pH range of 6-9; the Km values for NAD and formate are 1 . 10(-4) and 1,3 . 10(-2) M, respectively. Formate dehydrogenase is inhibited by p-chloromercurybenzoate, iodoacetate, dithionitrobenzoate and azide.
Assuntos
Aldeído Oxirredutases/metabolismo , Candida/enzimologia , Formiato Desidrogenases/metabolismo , Formiato Desidrogenases/isolamento & purificação , Concentração de Íons de Hidrogênio , Cinética , Peso Molecular , NADRESUMO
NAD-Dependent formate dehydrogenase (FDH) has been isolated from methylotrophyc strain Bacterium sp 1 by (NH4)2SO4 fractionation of cell extract, ion-exchange chromatography and preparative isotachophoresis. Preparation of FDH is homogeneous in analytical polyacrylamide gel electrophoresis and under ultracentrifugation. Sedimentation coefficient of FDH is 4.9S. Mikhaelis constants are 1.1-10(-4) M for NAD and 1.5-10(-2) M for formate. In the absence of sulfhydril compounds FDH is unstable, but it is stable in the presence of mercaptoethanol or ditiotreitol.
Assuntos
Aldeído Oxirredutases/metabolismo , Bactérias/enzimologia , Aldeído Oxirredutases/isolamento & purificação , Formiatos , Cinética , Peso Molecular , NADRESUMO
A new strain of facultative-methylotrophic bacteria was isolated and identified as Pseudomonas oleovorans. The culture grew on the methanol-containing medium (up to 6%). In addition to methanol, bacterial growth was provided by different organic acids, multicarbon alcohols and carbohydrates. During growth bacteria synthesized extracellular polysaccharide (up to 400 mg/ml). The compound included glucose, galactose and xylose.