The interest pertaining to lactose, because it is the carbohydrate in the diet of the nursling, is magnified by virtue of a number of other more or less related considerations. Half of its molecule is composed of galactose, to which is attributed the importance of serving as a source of certain essential tissue constituents, particularly those of the nervous system. Is it to be concluded that t...

Catabolite repression by galactose was investigated in several strains of Saccharomyces cerevisiae grown on different carbon sources. Galactose repressed as much as glucose; raffinose was less effective. Full derepression was achieved with lactate. The functions tested were L-lactate ferricytochrome c oxidoreductase, NAD-glutamate dehydrogenase, and respiration. Galactose repression was observe...

UDP-galactose 4-epimerase (EC 5.1.3.2, Gal E) from Escherichia coli catalyzes the reversible reaction between UDP-galactose and UDP-glucose. In this study, the Gal E gene from E. coli, coding UDP-galactose 4-epimerase, was cloned into pYD1 plasmid and then transformed into Saccharomyces cerevisiae EBY100 for expression of Gal E on the cell surface. Enzyme activity analyses with EBY100 cells sho...

Carbon catabolite repression (CCR) refers to the ability of bacteria to preferentially utilize one carbon source over another. Phosphoenolpyruvate-dependent carbohydrate: phosphotransferase system (PTS) is the mechanism by which CCR is exerted. In the absence of preferred PTS-carbon sources, cAMP-CAP complexes are abundant and thus, the enzymes encoded in the lac operon can be expressed maximal...

Incomplete intestinal absorption of fructose might lead to abdominal complaints such as pain, flatulence and diarrhoea. Whether defect fructose transporters such as GLUT5 or GLUT2 are involved in the pathogenesis of fructose malabsorption is a matter of debate. The hydrogen production by colonic bacteria is used for diagnosis with the hydrogen breath test. However, the appropriate fructose test...

Background: Classic galactosemia (CG) is an inborn error of galactose metabolism caused by a deficiency the enzyme galactose-1-phosphate uridyltransferase (GALT). This causes conversion uridine diphosphate- glucose (UDP)-glucose and (Gal-1-P) to glucose-1-phosphate UDP-galactose. The absence this results in accumulation metabolites galactitol Gal-1-P. CG heterogeneous at clinical molecular leve...

Healthy subjects ingested2H2O.2H enriched the hydrogen bound to carbon 1 of blood glucose 1.3 to 1.8 times more than the hydrogens bound to carbon 6. Enrichment at carbon 1 was more than at carbon 5 after 14 h, but not after 42 h, of fasting. After overnight fasting, when [2,3-3H]succinate was infused, 34 times as much 3H was bound to carbon 6 as to carbon 1. On [1-2H,1-3H,1-14C]galactose infus...

Regulation of the beta-galactoside transport system in response to growth substrates in the extremely thermophilic anaerobic bacterium Thermotoga neapolitana was studied with the nonmetabolizable analog methyl-beta-D-thiogalactopyranoside (TMG) as the transport substrate. T. neapolitana cells grown on galactose or lactose accumulated TMG against a concentration gradient in an intracellular free...

Prolonged exposure of tissues to elevated blood sugar levels lead the formation advanced glycation end products (AGEs), thus contributing diabetic complications. Since vascular system is in immediate contact with blood, effects on aorta a major health concern. However, relative effect diffusion molecular through wall and rate AGE not known. In this study, we aim address issue by incubating exci...

Interaction between aspartic acid and D-glucose, D-galactose, and D-fructose has been studied by isothermal titration calorimetry, calorimetry of dissolution, and densimetry. It has been found that D-glucose and D-fructose form thermodynamically stable associates with aspartic acid, in contrast to D-galactose. The selectivity in the interaction of aspartic acid with monosaccharides is affected ...