A Glucose-6-Phosphate Dehydrogenase in Leuconostoc Mesenteroides

Abstract

Glucose fermentation by Leuconostoc me8enteroides has been shown to proceed via a mechanism which differs from the classical Embden-Meyerhof glycolytic scheme. DeMoss, Bard, and Gunsalus (1951) found no evidence in cell-free extracts of this organism for the key enzyme aldolae but showed that cellular suspensions ferment glucose to equimolar quantities of ethanol, C02, and lactate as obligatory products. The diphosphopyridine nucleotide linked dehydrogenases for D-3-phosphoglyceraldehyde, D(-) lactic acid, and ethanol were demonstrated, indicating some resemblance of the Leuconostoc mechanism to the classical glycolytic scheme. Fermentation of glucose-1-C'4 by cellular suspensions was reported by Gibbs and DeMoss (1951) and Gunsalus and Gibbs (1952) to yield C14 exclusively in C02 at six times the specific activity of the glucose fermented, whereas glucose-3,4-C04 yielded carboxyl labeled lactate, carbinol labeled ethanol, and unlabeled C02. These results support the data obtained with enzyme extracts and, in addition, demonstrate that both C02 and ethanol must arise by a previously undescribed fermentative pathway(s). The observation of a glucose-6-phosphate dehydrogenase in extracts of L. menteroide8, reported in preliminary form by DeMoss, Gunsalus, and Bard (1951), suggested the operation of an anaerobic counterpart of the oxidative hexosemonophosphate pathway via phosphogluconic acid as the fermentative mechanism involved. Such an oxidative system, previously recognized only in aerobic organisms and studied by Warburg and Christian (1932), Lipmann (1936), and Dickens (1938), has been described recently in detail by Horecker and co-workers

Site‐directed mutagenesis to facilitate X‐ray structural studies of leuconostoc mesenteroides glucose 6‐phosphate dehydrogenase

“…Glucose 6-phosphate dehydrogenase (G6PD) (E.C. 1.1.1.49) from Leuconostoc mesenteroides is one such enzyme (De Moss et al, 1953). Our investigation of this enzyme has been motivated by a desire to understand the mechanism whereby the enzyme selects NAD or NADP for catalysis and the protein structural basis of this dual coenzyme specificity.Earlier work (summarized by Levy [1989]) demonstrated that the NAD-and NADP-linked reactions catalyzed by L. mesenteroides G6PD proceed via different kinetic mechanisms, and that this difference appears to be the basis upon which the enzyme selects the appropriate coenzyme.…”

“…Glucose 6-phosphate dehydrogenase (G6PD) (E.C. 1.1.1.49) from Leuconostoc mesenteroides is one such enzyme (De Moss et al, 1953). Our investigation of this enzyme has been motivated by a desire to understand the mechanism whereby the enzyme selects NAD or NADP for catalysis and the protein structural basis of this dual coenzyme specificity.…”

Feeding gelatinized carbohydrate in the diets of magur,Clarias batrachus(Linnaeus, 1758): Effects on growth performance, enzyme activities and expression of muscle regulatory factors

“…Liver alanine aminotransferase (ALT) and aspartate aminotransferase (AST) was assayed as described by Wootton () with 0.2 M DL‐alanine and 2 mM L‐ketoglutarate and 0.2 M DL‐aspartic acid and 20 mM L‐ketoglutarate as the substrate, respectively. Glucose‐6‐phosphate dehydrogenase (G6PDH) activity in liver tissues was analysed by the method of De Moss, Gunsalus, and Bard (). The reaction mixture comprised 1.5 ml of 0.1 M Tris buffer (pH 7.8), 0.2 ml of 2.7 mM NADP, 0.1 ml of tissue homogenate, 1 ml of distilled water and 0.1 ml of 0.02 M glucose‐6‐phosphate (G6P) and absorbance was recorded at 340 nm at the 15 s interval for 3 min against distilled water.…”

Regulation and properties of glucose-6-phosphate dehydrogenase: A review

“…The third group of the enzyme can react approximately equally well with NAD and NADP. This class includes the enzyme from a number of bacterial strains such as Leuconostoc mesenteroides (Demoss et al, 1953;Olive et al, 1971), Pseudomonas aeruginosa (Ju-Fang et al, 1998), Pseudomonas W6 (Reuter et al, 1990), Streptomyces aureofaciens (Haghighi et al, 2005), Methylomonas M15 (Steinbach et al, 1978). In dog liver G6PD NADP was replaced by d-NADP (Deamino NADP).…”