Gene/Protein
Disease
Symptom
Drug
Enzyme
Compound
Pivot Concepts:
Gene/Protein
Disease
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Drug
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Target Concepts:
Gene/Protein
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Query: EC:1.6.99.3 (
diaphorase
)
5,903
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
Delta1-pyrroline-5-carboxylate dehydrogenase (P5CDh) catalyzes the conversion of
Delta1
-pyrroline-5-carboxylate to glutamate in a reaction requiring NADP+ as a cofactor.
Delta1
-pyrroline-5-carboxylate is formed in liver from proline by proline oxidase (EC number not assigned) or from ornithine via ornithine aminotransferase. A spectrophotometric assay for P5CDh was shown to be valid if rotenone was included in the assay to prevent reoxidation of NADH. Using this new assay, liver was fractionated using differential centrifugation and the distribution of P5CDh was compared to that of appropriate marker enzymes. P5CDh is enriched only in the mitochondrial fractions, as are the mitochondrial enzymes, succinate
cytochrome c reductase
, proline oxidase, glutaminase, and ornithine aminotransferase. Thus, it can be concluded that P5CDh occurs only in mitochondria, not in both mitochondria and cytoplasm, as had previously been reported.
...
PMID:Assay and subcellular localization of pyrroline-5-carboxylate dehydrogenase in rat liver. 1553 70
Many commensal oral streptococci generate H
2
O
2
via pyruvate oxidase (SpxB) to inhibit the growth of competing bacteria like Streptococcus mutans, a major cariogenic species. In Streptococcus sanguinis SK36 (SK36) and Streptococcus gordonii
DL1
(
DL1
), spxB expression and H
2
O
2
release are subject to carbon catabolite repression by the catabolite control protein A (CcpA). Surprisingly, ccpA deletion mutants of SK36 and
DL1
fail to inhibit S. mutans despite their production of otherwise inhibitory levels of H
2
O
2
. Using H
2
O
2
-deficient spxB deletion mutants of SK36 and
DL1
, it was subsequently discovered that both strains confer protection in trans to other bacteria when H
2
O
2
is added exogenously. This protective effect depends on the direct detoxification of H
2
O
2
by the release of pyruvate. The pyruvate dependent protective effect is also present in other spxB-encoding streptococci, such as the pneumococcus, but is missing from spxB-negative species like S. mutans. Targeted and transposon-based mutagenesis revealed Nox (putative H
2
O-forming
NADH dehydrogenase
) as an essential component required for pyruvate release and oxidative protection, while other genes such as sodA and dps play minor roles. Furthermore, pyruvate secretion is only detectable in aerobic growth conditions at biofilm-like cell densities and is responsive to CcpA-dependent catabolite control. This ability of spxB-encoding streptococci reveals a new facet of the competitive interactions between oral commensals and pathobionts and provides a mechanistic basis for the variable levels of inhibitory potential observed among H
2
O
2
-producing strains of commensal oral streptococci.
...
PMID:Pyruvate secretion by oral streptococci modulates hydrogen peroxide dependent antagonism. 3198 75
