Glycerol-phosphate dehydrogenase

Another pathway is the L-glycerol 3-phosphate shuttle (Figure 11). Cytosolic dihydroxyacetone phosphate is reduced by NADFl to s.n-glycerol 3-phosphate, catalyzed by s,n-glycerol 3-phosphate dehydrogenase, and this is then oxidized by s,n-glycerol 3-phosphate ubiquinone oxidoreductase to dihydroxyacetone phosphate, which is a flavoprotein on the outer surface of the inner membrane. By this route electrons enter the respiratory chain.from cytosolic NADH at the level of complex III. Less well defined is the possibility that cytosolic NADH is oxidized by cytochrome bs reductase in the outer mitochondrial membrane and that electrons are transferred via cytochrome b5 in the endoplasmic reticulum to the respiratory chain at the level of cytochrome c (Fischer et al., 1985). 

Adams, P.R., Harrison, R., and Inch, T.D., Dehydrogenation of a phosphonate substrate analogue by glycerol 3-phosphate dehydrogenase, Biochem.., 141, 729, 1974. 

Gly-3-PDH glycerol-3-phosphate dehydrogenase DHAP dihydroxyacetone phosphate CoASH Coenzyme A... 

The glycerol 3-phosphate is oxidised by glycerol 3-phosphate dehydrogenase to produce dihydroxyacetone phosphate... 

Figure 9.18 The glycerol phosphate shuttle. In the cytosol, NADH is oxidised in a reaction in which dihydroxyacetone phosphate is reduced to glycerol 3-phosphate, catalysed by glycerol-3-phosphate dehydrogenase (NAD linked) ...

Glycerol 3-phosphate can arise in two ways, either (i) from glycerol, via the enzyme glycerol kinase or (ii) from dihydroxyacetone phosphate, which is produced in glycolysis, by reduction with NADH, catalysed by glycerol-3-phosphate dehydrogenase ... 

Glyceraldehyde Malate dehydrogenase 7.7.7.37 0 Glycerol 3-phosphate dehydrogenase 7.7.7.8... 

Glycerol-3-phosphate dehydrogenase (NAD ) [EC 1.1.1.8] catalyzes the reaction of xn-glycerol 3-phosphate with NAD+ to produce glycerone phosphate (or, dihydroxyacetone phosphate) and NADH. 1,2-Propanediol phosphate and glycerone sulfate can also act as substrates, having a weaker affinity. 

Fig. 9. The action of glycerol-3-phosphate dehydrogenase on 3,4-dihydroxybutylar-sonic acid.

Glycerol-3-phosphate may be used as a substrate for the MRC in a subset of tissues. It is conveniently added after malonate when measuring either complex II (allowing measurement of glycerol-3-phosphate dehydrogenase EC 1.1.95.5) or complex II—III... 

Z F6P + ATP + 2 NADH + H+ <-> 2 glycerol-3-phosphate + ADP + 2 NAD+ where F6P is fructose-6-phosphate, FDP is fructose-1,6-diphosphate, DHA-P is dihydroxyacetone phosphate, TIM is triosephosphate isomerase, and GDH is glycerol-3-phosphate dehydrogenase. The oxidation of NADH is a measure of the 6-PFK activity and is determined photometrically (decrease of OD per minute) [4]. 

L-Glycerol-3-phosphate dehydrogenase (GDH, from rabbit muscle) [9075,65-4] M4 78,000... 

L-Glycerol-3-phosphate dehydrogenase (GDH, from rabbit muscle) [9075,65-4] M4 78,000 [EC 1.1.1.8]. Recrystd by adding (NH4)2S(>4 till 0.45 saturation at pH 5.5 at 4° and the small amount of ppte is removed then satd (NH4)2S04 is added dropwise from time to time over several days in the cold room. 

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