Dehydrogenases sorbitol dehydrogenase

The liver appeared to be a target organ for hexachloroethane following oral administration. When one dose of 500 mg/kg was administered in an olive oil aqueous emulsion to male sheep, the levels of glutamate dehydrogenase, sorbitol dehydrogenase, ornithine carbamyl transferase, and aspartate aminotransferase in serum increased in the 2-day period after compound administration and then normalized (Fowler 1969b). Hexachloroethane had no effect on bromsulphthalein uptake from the blood by liver cells, but the transfer of this dye to bile was reduced in sheep exposed to doses of 500-1,000 mg/kg/day. 

RUBREDOXIN NAD REDUCTASE SERINE DEHYDROGENASE SORBITOL DEHYDROGENASE XANTHINE DEHYDROGENASE NAD formation,... 

Reductions catalyzed by glycerol dehydrogenase, sorbitol dehydrogenase, mannitol dehydrogenase, and aldose reductases formation of polyols from carbohydrates. 

Polyol dehydrogenase. Sorbitol dehydrogenase. L-iditol + NAD(+) = L-sorbose + NADH. 

The bioluminescent determinations of ethanol, sorbitol, L-lactate and oxaloacetate have been performed with coupled enzymatic systems involving the specific suitable enzymes (Figure 5). The ethanol, sorbitol and lactate assays involved the enzymatic oxidation of these substrates with the concomitant reduction of NAD+ in NADH, which is in turn reoxidized by the bioluminescence bacterial system. Thus, the assay of these compounds could be performed in a one-step procedure, in the presence of NAD+ in excess. Conversely, the oxaloacetate measurement involved the simultaneous consumption of NADH by malate dehydrogenase and bacterial oxidoreductase and was therefore conducted in two steps. 

Figure 5. Example of dehydrogenase reactions which can be coupled with the bienzymatic bacterial bioluminescent system. ADH = alcohol dehydrogenase (EC 1.1.1.1), SDH = sorbitol dehydrogenase (EC 1.1.1.14), LDH = lactate dehydrogenase (EC 1.1.1.27), MDH = malate dehydrogenase (EC 1.1.1.37).

Sorbitol Sorbitol dehydrogenase, bacterial luciferase FMA-NADH 60... 

Chronic copper poisoning in domestic sheep is first characterized by a period of passive accumulation of copper in the tissues. This period varies from a few weeks to more than a year. During this time the animal appears outwardly normal although the liver may contain more than 1000 mg Cu/kg DW and plasma activities of aspartate transaminase, sorbitol dehydrogenase, lactic... 

In clinical chemistry however, these systems have not been differentiated as yet. Since the oxidation of an alcohol corresponds to the reduction of a ketose or an aldose, the designations ketose reductase and aldose reductase, respectively, were suggested (H4, W14). In this paper however, the enzyme or enzyme system will be named polyol or sorbitol dehydrogenase (SDH), although the latter expression does not characterize exacdy the enzyme s function in a general biochemical sense. But sorbitol or fructose have been commonly used as substrates in clinical chemical investigations. 

Different preparative procedures have been shown to yield protein fractions which are able to catalyze different types of reactions with respect to their requirement of either NAD or NADP as coenzymes [cf. Eqs. (19), (20), and (21)]. In sera of mice poisoned by carbon tetrachloride we found polyol dehydrogenases catalyzing the oxidation of the following polyols (a) with NAD sorbitol, ribitol, mannitol (b) with NADP sorbitol, ribitol. Erythritol and mt/o-inositol were not attacked at all. Figures 8 and 9 show the results of these determinations performed at pH 9.6. In the NAD system sorbitol and ribitol are oxidized at exactly the same rate, while in the NADP system ribitol does not reach the rate of sorbitol. The ratio NAD NADP for sorbitol is calculated to be 4.20 and for ribitol 5.50. Mannitol is oxidized at 23% of the rate of sorbitol. 

Fic. 8. NAD polyol dehydrogenase in sera of CCl4-poisoned mice sorbitol, ribitol, and mannitol oxidation (pH 9.6 polyols as substrates). 

The role that polyol dehydrogenases play in metabolism has scarcely been elucidated. Approaches were made by investigating the metabolic fate of C14-labeled sorbitol after oral and parenteral administration. It has been found that in normal animals C1402 was expired following the administration of labeled sorbitol, while eviscerated, liverless subjects showed no C1402 expiration under these conditions, thus confirming... 

Hepati c 10 (significant increases in serum sorbitol dehydrogenase) ... 

SDH = sorbitol dehydrogenase SGPT = serum glutamic pyruvic transaminase wk = week yr = year(s)... 

Fig. 6.7 A FAC-MS experiment for ligand ranking. Eight ligands for sorbitol dehydrogenase were infused, spanning a range of 2 pM to 8 nM [10]. All ligands were applied at 1 pM concentration, ensuring operation in the nonlinear region of the binding isotherm. Adapted with permission from Elsevier.

SORBITOL DEHYDROGENASE FRUCTOSE-1,6-BISPHOSPHATASE FRUCTOSE-2,6-BISPHOSPHATASE D-Fructose 2,6-bisphosphate, 6-PHOSPHOFRUCTO-2-KINASE Fructose-1,6-bisphosphate aldolase, ALDOLASE... 

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