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

Postmortem changes in mitochondrial respiratory enzymes (Complex I-IV and NAD(+)-linked dehydrogenases in the TCA cycle) were studied in mouse brains and human frontal lobes. In mouse brains, activities of the enzymes studied were generally stable for as long as 12 h after cervical dislocation, except for the alpha-ketoglutarate dehydrogenase complex and NADP(+)-linked isocitrate dehydrogenase. In human frontal cortices, only NADH-ubiquinone reductase (Complex I) activity showed significant negative correlation with the duration between the patient's death and the freezing of the brain. No correlations between the activities of the enzymes studied and the age of the patients were noted. As most of our patients were 50 years of age or above, absence of the correlation cannot be extended to younger patients. From our observation, it was felt that analyses of these mitochondrial enzymes in human autopsy brains would give meaningful data. Preliminary observation in Parkinson's disease revealed a small but a significant decrease in the activity of Complex III in the striatum as compared with the control. Although, significance of our observation is not yet known, further studies on this line appear to be important to elucidate pathogenesis of Parkinson's disease.
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PMID:Postmortem changes in mitochondrial respiratory enzymes in brain and a preliminary observation in Parkinson's disease. 235 87

Interaction between the alpha-ketoglutarate dehydrogenase complex and NAD+-dependent isocitrate dehydrogenase was detected with a variety of techniques including polyethylene glycol precipitation, ultracentrifugation, and centrifugal gel filtration on a Sepharose 6B column. The interaction was specific in that citrate synthase, cytosolic malate dehydrogenase, and NADP-dependent isocitrate dehydrogenase did not interact with alpha-ketoglutarate dehydrogenase complex. The interaction was not inhibited by either 0.1 M KCl or 0.4 M (NH4)2SO4, but was completely prevented by 5% glycerol. A new method for the preparation of NADH: ubiquinone oxidoreductase resulted in an enzyme having a protein subunit composition similar to that of classical complex I preparation. Evidence is given for the existence of ternary complexes containing NADH:ubiquinone oxidoreductase-alpha-ketoglutarate dehydrogenase complex-NAD-dependent isocitrate dehydrogenase and NADH: ubiquinone oxidoreductase-alpha-ketoglutarate dehydrogenase complex-succinate thiokinase. These data suggest that a part of the citric acid cycle may be located in the vicinity of NADH: ubiquinone oxidoreductase. These complexes may facilitate the transport of metabolites among these enzymes without their equilibrating with the whole compartment.
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PMID:Interaction between NAD-dependent isocitrate dehydrogenase, alpha-ketoglutarate dehydrogenase complex, and NADH:ubiquinone oxidoreductase. 311 Jan 60

Environmental (acute and chronic temperature, osmotic, hypoxic and pH) stress challenges the cellular redox balance and can lead to the increased production of reactive oxygen species (ROS). This review provides an overview of the reactions producing and scavenging ROS in the mitochondria, endoplasmic reticulum (ER) and peroxisome. It then compares these reactions with the findings of a number of studies investigating the proteomic responses of marine organisms to environmentally induced oxidative stress. These responses indicate that the thioredoxin-peroxiredoxin system is possibly more frequently recruited to scavenge H2O2 than the glutathione system. Isoforms of superoxide dismutase (SOD) are not ubiquitously induced in parallel, suggesting that SOD scavenging activity is sometimes sufficient. The glutathione system plays an important role in some organisms and probably also contributes to protecting protein thiols during environmental stress. Synthesis pathways of cysteine and selenocysteine, building blocks for glutathione and glutathione peroxidase, also play an important role in scavenging ROS during stress. The increased abundance of glutaredoxin and DyP-type peroxidase suggests a need for regulating the deglutathionylation of proteins and scavenging of peroxynitrite. Reducing equivalents for these scavenging reactions are generated by proteins of the pentose phosphate pathway and by NADP-dependent isocitrate dehydrogenase. Furthermore, proteins representing reactions of the tricarboxylic acid cycle and the electron transport system generating NADH and ROS, including those of complex I, II and III, are frequently reduced in abundance with stress. Protein maturation in the ER likely represents another source of ROS during environmental stress, as indicated by simultaneous changes in ER chaperones and antioxidant proteins. Although there are still too few proteomic analyses of non-model organisms exposed to environmental stress for a general pattern to emerge, hyposaline and low pH stress show different responses from temperature and hypoxic stress. Furthermore, comparisons of closely related congeners differing in stress tolerance start to provide insights into biochemical processes contributing to adaptive differences, but more of these comparisons are needed to draw general conclusions. To fully take advantage of a systems approach, studies with longer time courses, including several tissues and more species comparisons are needed.
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PMID:Proteomic responses to environmentally induced oxidative stress. 2608 64