The metabolism of deoxy-fluoromonosaccharides by Pseudomonas fluorescens.

Abstract

The natural ocourrence and the biochemistry of carbon- fluorine compounds, with special reference to fluorocarbohydrates and related compounds, is reviewed. A study of the metabolism of 3-deoxy-3-fluoro-D-glucose and 4-deoxy-4-fluoro-D-glucose by Ps.fluorescens A.3.12. has been undertaken. METABOLISM OF 3-DEOXY-3-FLUORO-D-GLUCOSE. (1) 3-deoxy-3-fluoro-D-glucose cannot serve as a source of carbon for the growth of Ps.fluorescens A.3.12. and reduces the extent of bacterial growth on glucose. (2) Resting cells of glucose-grown Ps. fluorescens A.3.12. oxidise 3-deoxy-3-fluoro-D-glucose to an extent of one atom of oxygen per molecule of substrate with the formation of a product identified as 3-deoxy-3-fluoro-D-gluconic acid. (3) Chemically synthesised 3-deoxy-3-fluoro-D-gluconic acid is oxidised by resting cells of glucose-grown Ps. fluorescens A.3.12. to an extent of one atom of oxygen per molecule of substrate. (4) Cell-free extracts prepared from glucose-grown Ps. fluorescens A.3.12. oxidise 3-deoxy-3-fluoro-D-glucose and 3-deoxy-3-fluoro-D-gluconic acid to an extent of two atoms of oxygen and one atom of oxygen per molecule of substrate respectively. Evidence is presented which indicates that 3-deoxy-3-fluoro- D-glucose is oxidised by the bacterial glucose oxidase (KM=18.2mMolar) and that 3-deoxy-3-fluoro-D-gluconic acid is oxidised by the bacterial gluconate oxidase (KM=11.8mMolar). The product resulting from the two-stage oxidation of 3-deoxy-3-fluoro-D-glucose has been isolated and characterised as 3-deoxy-3- fluoro-2-keto-D-gluconic acid. (5) 3-deoxy-3-fluoro-D-glucose, 3-deoxy-3-fluoro-D-gluconic acid and 3-deoxy-3--fluoro-2-keto-D-gluconic acid are not substrates for the bacterial gluconokinase and 2-ketogluconokinase. 3-deoxy-3-fluoro-D-glucose and 3-deoxy-3-fluoro-D-gluconic acid are competitive inhibitors of gluconokinase with Ki values 47.5 mMolar and 14.8 mMolar respectively. (6) 3-deoxy-3-fluoro-D-gluconic acid and 3-deoxy-3-fluoro-2-keto-D-gluconic acid are not substrates for the bacterial 6-phosphogluconate dehydrase. 3-deoxy-3-fluoro-2-keto-D-gluconic acid is not cleaved by the bacterial 2-keto-3-deoxy-6-phosphogluconate aldolase. METABOLISM OF 4-DEOXY-4-FLUORO-D-GLUCOSE. (1) Incubation of resting cells of glucose-grown Ps. fluorescens A.3.12. with 4-deoxy-4-fluoro-D-glucose results in the release of fluorine as free fluoride ion with no accompanying oxidation. (2) Cell-free extracts prepared from glucose-grown Ps. fluorescens A.3.12. oxidise 4-deoxy-4-fluoro-L-glucose to an extent of two atoms of oxygen per molecule of substrate, without the liberation of fluoride ion. (3) 4-deoxy-4-fluoro-D-glucose cannot serve as a source of carbon for the growth of Ps. fluorescens A.3.12. and reduces the extent of bacterial growth on glucose. The significance of the above results in relation to carbohydrate metabolism and transport is discussed.

Date of Award	1973
Original language	English
Awarding Institution	University of Bath