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Alanine oxidation

In most mammalian muscles, amino acids are not a major fuel for oxidative metabolism, although they may be in numerous other animals. When amino acids are the fuels being combusted, they are metabolized by pathways that all ultimately feed into the Krebs cycle, where the intermediates can be fully metabolized (figure 2.3). Being at about the same oxidation state as carbohydrates, the ATP yields of amino acids during oxidation are also similar. For example, alanine oxidation... [Pg.23]

Answer Lactate and alanine are converted to pyruvate by their respective dehydrogenases, lactate dehydrogenase and alanine dehydrogenase, producing pyruvate and NADH + H+ and, in the case of alanine, NH. Complete oxidation of 1 mol of pyruvate to C02 and H20 produces 12.5 mol of ATP via the citric acid cycle and oxidative phosphorylation (see Table 16-1). In addition, the NADH from each dehydrogenase reaction produces 2.5 mol of ATP per mole of NADH reoxidized. Thus oxidation produces 15 mol of ATP per mole of lactate. Urea formation uses the equivalent of 4 mol of ATP per mole of urea formed (Fig. 18-10), or 2 mol of ATP per mol of NH4. Subtracting this value from the energy yield of alanine results in 13 mol of ATP per mole of alanine oxidized. [Pg.199]

The intracellular levels of ammonium ions, in S. noursei, are also influenced by the action of alanine dehydrogenase [102]. Ammonium liberated by alanine oxidation is available for the biosynthesis of glutamine via glutamine synthetase. 0-aminobenzoic acid represses both enzymes while stimulating formation of glutamate dehydrogenase and the antibiotic. Cephalosporin biosynthesis appears to be regulated by the same mechanism [103]. [Pg.968]

The resulting -aminocaproic acid hydrochloride is treated in a manner similar to that used in the preparation of df-alanine (Org. Syn. Coll. Vol. i, 20). The hydrochloride is dissolved in r 1. of water in a 1.5-I. beaker and treated successively with 50 g. of powdered litharge, 25 g. of powdered litharge, 5 g. of freshly precipitated lead hydroxide, 25 g. of powdered silver oxide (Note 2), and finally hydrogen sulfide. During this procedure, the original volume is maintained by the addition of small amounts of water. [Pg.7]

Phosphorus pentachloride, for conversion of pentaacetylgluconic add to add chloride, 41, 80 for oxidation of cycloheptatriene to tropylium fluoborate, 43, 101 with cyanoacetic acid, 41, 5 Phosphorus tribromide, reaction with 1.5-hexadien-3-ol, 41, 50 Phthalic anhydride, reaction with L-phenylalanine to yield N-phthalyl-L-phenylalanine, 40, 82 Phthalic monoperacid, 42, 77 N-Phthalyl-i.-alanine, 40, 84 N-Phthalyl-/3-alanine, 40, 84 N-Phthalylglycine, 40, 84 N-Phthalyl-l-/5-phenylalanine, 40, 82... [Pg.120]

The lower redox potential in menaquinone-oxidizing be complexes can be attributed to the absence of the hydrogen bond from the Oy of Ser 163 (ISF)/Ser 130 (RFS) to the bridging sulfur S-1 (see Section III,B,2). This serine is completely conserved in Rieske proteins of bci and bef complexes, but in all sequences of Rieske proteins from menaquinone-oxidizing be complexes, alanine or glycine is found in... [Pg.137]

The third reason for favoring a non-radical pathway is based on studies of a mutant version of the CFeSP. This mutant was generated by changing a cysteine residue to an alanine, which converts the 4Fe-4S cluster of the CFeSP into a 3Fe-4S cluster (14). This mutation causes the redox potential of the 3Fe-4S cluster to increase by about 500 mV. The mutant is incapable of coupling the reduction of the cobalt center to the oxidation of CO by CODH. Correspondingly, it is unable to participate in acetate synthesis from CH3-H4 folate, CO, and CoA unless chemical reductants are present. If mechanism 3 (discussed earlier) is correct, then the methyl transfer from the methylated corrinoid protein to CODH should be crippled. However, this reaction occurred at equal rates with the wild-type protein and the CFeSP variant. We feel that this result rules out the possibility of a radical methyl transfer mechanics and offers strong support for mechanism 1. [Pg.324]

Naumann E, H Hippe, G Gottschalk (1983) Betaine new oxidant in the Stickland reaction and methanogen-esis from betaine and L-alanine by a Clostridium sporogenes-Methanosarcina barkeri coculture. Appl Environ Microbiol 45 474-483. [Pg.332]

Stickland LH (1935b) Studies in the metabolism of the strict anaerobes (genus Clostridium). III. The oxidation of alanine by Cl. sporogenes. IV. The reduction of glycine by Cl. sporogenes. Biochem J 29 898. [Pg.334]

Kaczorowski G, L Shaw, R Laura, C Walsh (1975) Active transport in Escherichia coli B membrane vesicles. Differential inactivating effects from the enzymatic oxidation of P-chloro-L-alanine and P-chloro-D-alanine. J Biol Chem 250 8921-8930. [Pg.373]

Many dehydrogenase enzymes catalyze oxidation/reduction reactions with the aid of nicotinamide cofactors. The electrochemical oxidation of nicotinamide adeniiw dinucleotide, NADH, has been studied in depthThe direct oxidation of NADH has been used to determine concentration of ethanol i s-isv, i62) lactate 157,160,162,163) pyTuvate 1 ), glucose-6-phosphate lactate dehydrogenase 159,161) alanine The direct oxidation often entails such complications as electrode surface pretreatment, interferences due to electrode operation at very positive potentials, and electrode fouling due to adsorption. Subsequent reaction of the NADH with peroxidase allows quantitation via the well established Clark electrode. [Pg.65]

L-tryptophan is compulsory, the biosynthetic machinery displays wide latitude in its ability to condense a second auxiliary amino acid—L-alanine in the case of (+)-ll,ll -dideoxyverticillin A (1)—to afford a tryptophan-derived diketopiperazine intermediate 13. Mirroring Woodward and Robinson s biogenetic hypothesis for the calycanthaceous alkaloids, single-electron oxidation of the electron-rich tryptophan residue would likely initiate an oxidative dimerization of the diketopiperazine precursor with concomitant cyclization to yield the octacyclic intermediate 17. Subsequent A-methylation of the amides would then yield an unembellished skeletal core of the dimeric epipolythiodiketopiperazine alkaloids. The first step en route... [Pg.215]


See other pages where Alanine oxidation is mentioned: [Pg.4195]    [Pg.2307]    [Pg.234]    [Pg.4195]    [Pg.2307]    [Pg.234]    [Pg.443]    [Pg.45]    [Pg.49]    [Pg.339]    [Pg.624]    [Pg.196]    [Pg.455]    [Pg.323]    [Pg.173]    [Pg.176]    [Pg.1028]    [Pg.273]    [Pg.250]    [Pg.117]    [Pg.111]    [Pg.138]    [Pg.154]    [Pg.159]    [Pg.234]    [Pg.244]    [Pg.142]    [Pg.352]    [Pg.339]    [Pg.250]    [Pg.266]    [Pg.728]    [Pg.155]    [Pg.91]    [Pg.220]    [Pg.223]   
See also in sourсe #XX -- [ Pg.126 ]

See also in sourсe #XX -- [ Pg.138 ]




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