Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:1.4.1.2 (glutamate dehydrogenase)
 4,380 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Metabolic pathways involved in the formation of cytotoxic end products by Porphyromonas gingivalis were studied. The washed cells of P. gingivalis ATCC 33277 utilized peptides but not single amino acids. Since glutamate and aspartate moieties in the peptides were consumed most intensively, a dipeptide of glutamate or aspartate was then tested as a metabolic substrate of P. gingivalis. P. gingivalis cells metabolized glutamylglutamate to butyrate, propionate, acetate, and ammonia, and they metabolized aspartylaspartate to butyrate, succinate, acetate, and ammonia. Based on the detection of metabolic enzymes in the cell extracts and stoichiometric calculations (carbon recovery and oxidation/reduction ratio) during dipeptide degradation, the following metabolic pathways were proposed. Incorporated glutamylglutamate and aspartylaspartate are hydrolyzed to glutamate and aspartate, respectively, by dipeptidase. Glutamate is deaminated and oxidized to succinyl-coenzyme A (CoA) by glutamate dehydrogenase and 2-oxoglutarate oxidoreductase. Aspartate is deaminated into fumarate by aspartate ammonia-lyase and then reduced to succinyl-CoA by fumarate reductase and acyl-CoA:acetate CoA-transferase or oxidized to acetyl-CoA by a sequential reaction of fumarase, malate dehydrogenase, oxaloacetate decarboxylase, and pyruvate oxidoreductase. The succinyl-CoA is reduced to butyryl-CoA by a series of enzymes, including succinate-semialdehyde dehydrogenase, 4-hydroxybutyrate dehydrogenase, and butyryl-CoA oxidoreductase. A part of succinyl-CoA could be converted to propionyl-CoA through the reactions initiated by methylmalonyl-CoA mutase. The butyryl- and propionyl-CoAs thus formed could then be converted into acetyl-CoA by acyl-CoA:acetate CoA-transferase with the formation of corresponding cytotoxic end products, butyrate and propionate. The formed acetyl-CoA could then be metabolized further to acetate.
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PMID:Metabolic pathways for cytotoxic end product formation from glutamate- and aspartate-containing peptides by Porphyromonas gingivalis. 1094 8

Pathways for amino acid metabolism by Prevotella intermedia and Prevotella nigrescens were investigated. Prevotella strains grew anaerobically in tryptone-based medium and their growth increased upon the addition of aspartate to the medium. Washed cells of tryptone-grown strains metabolized aspartate to succinate, acetate, fumarate, malate, formate and ammonia, while from tryptone they produced isobutyrate and isovalerate in addition to the end products from aspartate. Cell extracts obtained from the tryptone-grown cells had aspartate ammonia-lyase for the conversion of aspartate to fumarate. Methylviologen-dependent fumarate reductase was found to reduce fumarate to succinate. A series of enzymatic activities, including fumarase, NAD-dependent malate dehydrogenase, oxaloacetate decarboxylase, methylviologen-dependent pyruvate oxidoreductase, phosphotransacetylase and acetate kinase, was detected for the oxidative conversion of fumarate to acetate. Pyruvate formate-lyase and NAD-dependent formate dehydrogenase were also found for the production and consumption of formate, respectively. Methylviologen: NAD(P) oxidoreductase was found to be responsible for linkage between these reductive and oxidative pathways. Furthermore, the cell extracts had branched-chain amino acid aminotransferase and methylviologen-dependent branched-chain 2-oxoacid oxidoreductase, concomitantly with NAD-dependent glutamate dehydrogenase. Valine and leucine could be converted to isobutyryl CoA and isovaleryl CoA, respectively, through the sequential catalyses of these enzymes, and consequently to isobutyrate and isovalerate, respectively.
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PMID:Pathways for amino acid metabolism by Prevotella intermedia and Prevotella nigrescens. 1115 72