L-Glycerol-3-phosphate

Triacylglycerols arise not by acylation of glycerol itself but by a sequence of steps m which the first stage is acyl transfer to l glycerol 3 phosphate (from reduction of dihy droxyacetone 3 phosphate formed as described m Section 25 21) The product of this stage IS called a phosphatidic acid... 

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). 

Oxidation by raising the pH (to 7.5) phytase activity is switched off hydrolysis is prevented. Oxidation of L-glycerol-3-phosphate to DHAP by GPO at 55% glycerol (v/v) is quantitative. Catalase is added to suppress the build-up of hydrogen peroxide. The D-isomer is converted back into glycerol and phosphate in the last step. 

L-glycerol-3-phosphate oxidase, l-GPO (EC 1.1.3.21, from Thermophilus bacillus) (45 units)... 

This enzyme [EC 2.7.8.5] (also referred to as phosphati-dylglycerophosphate synthase, glycerophosphate phos-phatidyltransferase, and 3-phosphatidyl-l -glycerol-3 -phosphate synthase) catalyzes the reaction of CDP-diac-ylglycerol with glycerol 3-phosphate to produce CMP and 3-(3-phosphatidyl)glycerol 1-phosphate. 

DHAP can be prepared by oxidation of L-glycerol-3-phosphate (L- G3P) catalyzed by glycerophosphate oxidase, coupled with hydrogen peroxide decomposition in the presence of catalase (Scheme 4.5) [14]. More recently, this synthetic route has... 

GOX (glucose oxidase), 631, 636, 637 GPC (unsaturated glycerophosphocholine), 737 GPO (l-glycerol-3-phosphate oxidase), 633 Graft polymers cellulose, 698 cross-linking initiators, 706 ozonized polymers, 622 Griesbaum co-ozonolysis, 1,2,4-tiioxane antimalarials, 1331... 

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. 

The first steps of glycerophospholipid synthesis are shared with the pathway to triacylglycerols (Fig. 21-17) two fatty acyl groups are esterified to C-l and C-2 of L-glycerol 3-phosphate to form phosphatidic acid. Commonly but not invariably, the fatty acid at C-l is saturated and that at C-2 is unsaturated. A second route to phosphatidic acid is the phosphorylation of a diacyl-glycerol by a specific kinase. 

The latest, and most advanced, technique uses an inexpensive flavine-dependent glycerol phosphate oxidase (GPO, EC 1.1.3.21), found in several microorganisms (Scheme 13), for air oxidation of L-glycerol 3-phosphate 65 to generate DHAP practically quantitatively and in high chemical purity [200]. A separate cofactor regeneration step has become obsolete because the reduced... 

Shvets and co-workers [301] have described a new synthesis of the phosphatidyl-inositol (435) by phosphorylation of the orthoester (437), derived from 2,3 4,5-di-0-cyclohexylidene-L-wyo-inositol, with 1,2-di-O-stearoyl-L-glycerol 3-phosphate in... 

The structure of L-glycerol 3-phosphate is shown in a Fischer projection. Translate the Fischer projection to a three-dimensional representation. 

The conversion of L-glycerol 3-phosphate to a phosphatidic acid does not affect any of the bonds to the stereogenic center, nor does it alter the sequence rule ranking of the substituents. 

This enzyme utilizes in-glycerol 3-phosphate (L-glycerol 3-phosphate) and the 4-pro-S position of the coenzyme [38]. The primary structure of the rabbit muscle enzyme... 

The oxidation of L-glycerol 3-phosphate to dihydroxyacetone phosphate is catalyzed by two different enzymes. One is the cytoplasmic NAD-linked a-glycerophosphate dehydrogenase, and the other is the mitochondrial enzyme, which appears to contain flavin and iron. The latter enzyme was first studied by Green in 1936 (223). It was shown to be associated with respiratory particles, and widely distributed in animal tissues. The highest concentration of the enzyme was found in the brain. Lardy and co-workers (234) studied the enzyme in deoxycholate-solubilized particles obtained from skeletal muscle, confirmed the finding... 

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