A-Glycerophosphate oxidase

Evidence for the existence of an a-glycerophosphate oxidase system with three phosphorylation sites and sensitive to rotenone and piericidin A. FEBS Letters, 10 109-12. 

In the most commonly used methods, glycerophosphate is oxidized to dihydroxyacetone and H2O2 in a glycerophosphate oxidase-catalyzed reaction,... 

Iron deficiency is the most common nutritional cause of anemia in humans. It can result from inadequate iron intake, malabsorption, blood loss, or an increased requirement, as with pregnancy. When severe, it results in a characteristic microcytic, hypochromic anemia. Iron is an essential component of myoglobin heme enzymes such as the cytochromes, catalase, and peroxidase and the metalloflavoprotein enzymes, including xanthine oxidase and the mitochondrial enzyme a-glycerophosphate oxidase. Iron deficiency can affect metabohsm in muscle independent of the effect of anemia on delivery, possibly due to a reduction in the activity of iron-dependent mitochondrial enzymes. Iron deficiency also has been associated with behavioral and learning problems in children, abnormahties in catecholamine metabolism, and impaired heat production. 

Recently a variation of the above described approach was introduced. Rac-gly-cidol was treated with disodiumhydrogenphosphate and then oxidized by catalase and L-glycerophosphate oxidase to DHAP. These two steps were integrated with a RAMA-catalyzed step, yielding the phosphorylated aldol product. After adjusting the pH, phosphatase was added and the aldol could be isolated in good yield (Scheme 5.28) [48]. It can be assumed that all the above-mentioned... 

Fig. 3.1. A, The respiratory chain. Q and c stand for ubiquinone and cytochrome c, respectively. Auxiliary enzymes that reduce ubiquinone include succinate dehydrogenase (Complex II), a-glycerophosphate dehydrogenase and the electron-transferring flavoprotein (ETF) of fatty acid oxidation. Auxiliary enzymes that reduce cytochrome c include sulphite oxidase. B, Thermodynamic view of the respiratory chain in the resting state (State 4). Approximate values are calculated according to the Nernst equation using oxidoreduction states from work by Muraoka and Slater, (NAD, Q, cytochromes c c, and a oxidation of succinate [6]), and Wilson and Erecinska (b-562 and b-566 [7]). The NAD, Q, cytochrome b-562 and oxygen/water couples are assumed to equilibrate protonically with the M phase at pH 8 [7,8]. E j (A ,/ApH) for NAD, Q, 6-562, and oxygen/water are taken as —320 mV ( — 30 mV/pH), 66 mV (- 60 mV/pH), 40 mV (- 60 mV/pH), and 800 mV (- 60 mV/pH) [7-10]. FMN and the FeS centres of Complex I (except N-2) are assumed to be in redox equilibrium with the NAD/NADH couple, FeS(N-2) with ubiquinone [11], and cytochrome c, and the Rieske FeS centre with cytochrome c [10]. The position of cytochrome a in the figure stems from its redox state [6] and its apparent effective E -, 285 mV in...

Katakis and Heller [21] also applied the redox hydrogel to construct L-lactate and L-a-glycerophosphate sensors, where they observed electro-catalytic oxidation of both lactate and glycerol-3-phosphate at electrodes coated with three-dimensional redox polymer epoxy cross-linked networks which incorporated the respective oxidases. 

The FAD-requiring enzymes in mammalian systems include the D- and L-amino acid oxidases, mono- and diamine oxidases, glucose oxidase, succinate dehydrogenase, a-glycerophosphate dehydrogenase, and glutathione reductase. FMN is a cofactor for renal L-amino acid oxidase, NADH reductase, and a-hydroxy acid oxidase. In succinate dehydrogenase, FAD is linked to a histidyl residue in liver mitochondrial monoamine oxidase, to a cysteinyl residue. In other cases, the attachment is nonco-valent but the dissociation constant is very low. 

Bayne, R. A., Muse, K. E. and Roberts, J. F. (1969) Isolation of bodies containing the cyanide insensitive glycerophosphate oxidase of Trypanosoma equiperdum. Comp. Biochem. Physiol. 30 1049-1054. 

ALAndrostene-3,17-dione, effect on D-amino acid oxidase, X, 356 on choline acetylase, X, 362 on oxidation of a-glycerophosphate, X, 359, 360... 

In a commercially available assay, serum NTP catalyzes the hydrolysis of IMP to yield inosine, which is then converted to hypoxanthine by purine-nucleoside phosphorylase (EC 2.4.2.1). Hypoxanthine is oxidized to urate with xanthine oxidase (EC 1.2.3.2). Two moles of hydrogen peroxide are produced for each mole of hypoxanthine liberated and converted to uric acid. The formation rate of hydrogen peroxide is monitored by a spectrophotometer at 510nm by the oxidation of a chromogenic system. The effect of ALPs on IMP is inhibited by p-glycerophosphate. This material is substrate for ALP but not for NTP, and by forming substrate complexes with the former enzyme, it reduces the proportion of the total ALP activity that is directed to the hydrolysis of the NTP substrate, IMP. ... 

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