Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:1.6.5.3 (complex I)
 8,901 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Several analogs of 1-methyl-4-phenylpyridinium (MPP+) were evaluated for their affinity for the dopamine uptake system and their ability to inhibit NADH dehydrogenase (complex I) of the mitochondrial electron-transport chain. Moreover, these compounds were tested for their ability to cause selective dopaminergic neurotoxicity in cultured mesencephalic neurons. Simultaneous [3H]dopamine and gamma-amino-[14C]butyric acid uptake and immunocytochemical techniques were used as indices of neuronal damage in cultured cells. The compounds that were potent and selective dopaminergic neurotoxins had high affinity for the dopamine transport system, as measured by their ability to cause dopamine release, and were similar to MPP+ in inhibiting mitochondrial respiration. One compound (1-methyl-4-phenylpyrimidinium) had high affinity for the dopamine uptake system but was a weak inhibitor of mitochondrial respiration and, accordingly, was not neurotoxic. The 4'-alkylated analogs of MPP+, which were poor substrates for the dopamine uptake system and extremely potent inhibitors of mitochondrial respiration, caused a nonselective damage of neurons in culture. Analogs that were not substrates for the dopamine carrier and not inhibitors of mitochondrial respiration were not neurotoxic. This study describes the neurotoxicity of a number of analogs of MPP+ and highlights the importance of the dopamine uptake system and the ability to inhibit mitochondrial respiration as critical processes in conferring selectivity and neurotoxicity, respectively, to MPP+ and analogs, for dopaminergic neurons in culture.
 ...
PMID:Dopaminergic neurotoxicity of 1-methyl-4-phenylpyridinium analogs in cultured neurons: relationship to the dopamine uptake system and inhibition of mitochondrial respiration. 131 70

The enzymatic activity of five enzymes viz. Glutathione S-transferases, Esterases, NADH dehydrogenase, NADH oxidase and Glutathione reductase were assessed under the influence of Indole butyric acid (IBA) (400 ppm) in the nymphs (48-52h old) of mustard aphid, Lipaphis erysimi fed on radish plants treated for 13, 25 and 37h. The activity of Glutathione S-transferases, Esterases and NADH dehydrogenase increased compared to that found in the control of the same age group of nymphs and it was concluded that these enzymes might be involved in the metabolism of IBA. The other two enzymes, NADH oxidase and Glutathione reductase showed no significant increase in their activity compared to that in the control of the same age group. It was hypothesized that the latter enzymes do not play any significant role in the metabolism of IBA.
 ...
PMID:Evaluation of the possible role of five enzymes in the metabolism of IBA in mustard aphid, Lipaphis erysimi (Kalt.). 1552 74

Plants accumulate high levels of Gamma amino butyric acid (GABA) in response to different environmental stresses and GABA metabolism has different functions such as osmotic and pH regulation, bypass of tricarboxylic acid cycle, and C:N balance. The cytoplasmic male sterile (CMS) II mutant of Nicotiana sylvestris has a deletion in the mitochondrial gene nad7 which encodes the NAD7 subunit of complex I which causes increased leaf respiration, impaired photosynthesis, slower growth and increased amino acid levels. In this study we aimed to elucidate the role of GABA and GABA metabolism in different genotypes of the same plant system under salt stress (100mM NaCl) in short (24h) and long (7, 14 and 21 days) terms. We have investigated the differences in leaf fresh and dry weights, relative water content, photosynthetic efficiency (F(v)/F(m)), glutamate dehydrogenase (GDH, EC 1.4.1.4) and glutamate decarboxylase (GAD, EC 4.1.1.15) enzyme activities, GABA content and GAD gene expression profiles. GDH activity showed variations in CMSII and wild type (WT) plants in the first 24h. GAD gene expression profiles were in good agreement with the GAD enzyme activity levels in CMSII and WT plants after 24h. In long-term salinity, GAD activities increased in WT but, decreased in CMSII. GABA accumulation in WT and CMSII plants in short and long term was induced by salt stress. Variations in GDH and GAD activities in relation to GABA levels were discussed and GABA metabolism has been proposed to be involved in better performance of CMSII plants under long term salinity.
 ...
PMID:Contribution of Gamma amino butyric acid (GABA) to salt stress responses of Nicotiana sylvestris CMSII mutant and wild type plants. 2218 26