Gene/Protein
Disease
Symptom
Drug
Enzyme
Compound
Pivot Concepts:
Gene/Protein
Disease
Symptom
Drug
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Target Concepts:
Gene/Protein
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Query: EC:1.4.1.2 (
glutamate dehydrogenase
)
4,380
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
Acinetobacter lwoffii strain ISP4 metabolizes isophthalate rapidly compared with Pseudomonas aeruginosa strain
PP4
and Pseudomonas strain PPD. Isophthalate has been reported to be a potent competitive inhibitor of
glutamate dehydrogenase
(
GDH
). Exogenous supplementation of isophthalate with glutamate or alpha-ketoglutarate at 1 mM concentration caused strains
PP4
and PPD to grow faster than in the presence of isophthalate alone; however, no such effect was observed in strain ISP4. When grown on isophthalate, all strains showed activity of NADP-dependent
GDH
(NADP-GDH), while cells grown on glucose, 2x yeast extract-tryptone broth (2YT) or glutamate showed activities of both NAD-dependent
GDH
(NAD-GDH) and NADP-
GDH
. Activity staining, inhibition and thermal stability studies indicated the carbon source-dependent presence of two (
GDH
(I) and
GDH
(II)), three (
GDH
(A),
GDH
(B) and
GDH
(C)) and one (
GDH
(P)) forms of NADP-
GDH
in strains
PP4
, PPD and ISP4, respectively. The results demonstrate the carbon source-dependent modulation of different forms of NADP-
GDH
in these bacterial strains. This modulation may help the efficient utilization of isophthalate as a carbon source by overcoming the inhibitory effect on
GDH
.
...
PMID:Carbon source-dependent modulation of NADP-glutamate dehydrogenases in isophthalate-degrading Pseudomonas aeruginosa strain PP4, Pseudomonas strain PPD and Acinetobacter lwoffii strain ISP4. 1895 86
Pseudomonas aeruginosa strain
PP4
and Acinetobacter lwoffii strain ISP4 metabolize isophthalate as a sole source of carbon and energy. Isophthalate is known to be a competitive inhibitor of
glutamate dehydrogenase
(
GDH
), which is involved in C and N metabolism. Strain
PP4
showed carbon source-dependent modulation of NADP-
GDH
;
GDH
(I) was produced when cells were grown on isophthalate, while
GDH
(II) was produced when cells were grown on glucose. Strain ISP4 produced a single form of NADP-
GDH
,
GDH
(P), when it was grown on either isophthalate or rich medium (2YT). All of the forms of
GDH
were purified to homogeneity and characterized.
GDH
(I) and
GDH
(II) were found to be homotetramers, while
GDH
(P) was found to be a homohexamer.
GDH
(II) was more sensitive to inhibition by isophthalate (2.5- and 5.5-fold more sensitive for amination and deamination reactions, respectively) than
GDH
(I). Differences in the N-terminal sequences and electrophoretic mobilities in an activity-staining gel confirmed the presence of two forms of
GDH
,
GDH
(I) and
GDH
(II), in strain
PP4
. In strain ISP4, irrespective of the carbon source, the
GDH
(P) produced showed similar levels of inhibition with isophthalate. However, the specific activity of
GDH
(P) from isophthalate-grown cells was 2.5- to 3-fold higher than that of
GDH
(P) from 2YT-grown cells. Identical N-terminal sequences and electrophoretic mobilities in the activity-staining gel suggested the presence of a single form of
GDH
(P) in strain ISP4. These results demonstrate the ability of organisms to modulate
GDH
either by producing an entirely different form or by increasing the level of the enzyme, thus enabling strains to utilize isophthalate more efficiently as a sole source of carbon and energy.
...
PMID:Bypassing isophthalate inhibition by modulating glutamate dehydrogenase (GDH): purification and kinetic characterization of NADP-GDHs from isophthalate-degrading Pseudomonas aeruginosa strain PP4 and Acinetobacter lwoffii strain ISP4. 1993 55
