Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UNIPROT:Q8NEX9 (reductase)
 26,410 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Location of electron transport chain components in chloroplast membranes of chlamydomonas reinhardi, y-1 was investigated by use of proteolytic digestion with soluble or insolubilized trypsin. Digestion of intact membrane vesicles with soluble trypsin inactivates the water-splitting system, the 3-(3,4-dichlorophenyl)-1,1-dimethylurea inhibition site of Photosystem II, the electron transport between the two photosystems as well as the ferredoxin NADP reductase. Reduction of NADP with artificial electron donors for Photosystem I could be restored, however, by addition of purified reductase to trypsin-digested membranes. Electron transfer activities of Photosystems I and II reaction centers were resistant to trypsin digestion either from outside or from within the thylakoids when active trypsin was trapped inside the membrane vesicles by sonication and digestion carried out in the presence of trypsin inhibitor added from outside. In the latter case, the water-splitting system was also found to be resistant to digestion. Polyacrylamide-bound insolubilized trypsin inactivated only the ferredoxin NADP reductase. Photosynthetically active membranes obtained at different stages of development showed a basically similar behavior toward trypsin.
 ...
PMID:Trypsin-sensitive photosynthetic activities in chloroplast membranes from Chlamydomonas reinhardi, y-1. 0 Apr

The biosynthesis of fatty acids from malonyl-CoA and acetyl-CoA was investigated with an enzyme preparation which was purified 100-fold from Brevibacterium ammoniagenes. Fatty acids synthesized in the presence of D2O and stereospecifically deuterated NADPH and NADH were isolated and analyzed by mass chromatography to examine the localization of deuterium in the molecule. The following results were obtained: 1) HB hydrogen of NADPH was used for beta-ketoacyl reductase. 2) HB hydrogen of NADH was used for enoyl reductase. 3) Hydrogen atoms from water were found on the even-numbered methylene carbon atoms (2-hydrogen atoms per carbon atom) and some were also found on the odd-numbered methylene carbon atoms. 4) Hydrogen atoms from NADPH was found on the odd-numbered methylene carbon atoms (1 hydrogen per carbon). 5) Hydrogen atoms from NADH was also found on the odd-numbered methylene carbon atoms, but the number of incorporated hydrogen atoms was less than expected. The exchange of HB hydrogen of NADH with water catalyzed by enoyl reductase was suspected. 6) The exchange of methylene hydrogen atoms of malonyl-CoA with protons of water was suggested by 13C NMR analysis.
 ...
PMID:Stereochemical studies of hydrogen incorporation from nucleotides with fatty acid synthetase from Brevibacterium ammoniagenes. 1 49

The biosynthesis of fatty acids from malonyl-CoA and acetyl-CoA was investigated with an enzyme preparation which was purified 100-fold from Brevibacterium ammoniagenes. Fatty acids synthesized in the presence of D2O and stereospecifically deuterated NADPH and NADH were isolated and analyzed by mass chromatography to examine the localization of deuterium in the molecule. The following results were obtained: 1) HB hydrogen of NADPH was used for beta-ketoacyl reductase. 2) HB hydrogen of NADH was used for enoyl reductase. 3) Hydrogen atoms from water were found on the even-numbered methylene carbon atoms (2-hydrogen atoms per carbon atom) and some were also found on the odd-numbered methylene carbon. 4) Hydrogen atoms from NADPH were found on odd-numbered methylene carbon atoms (1-hydrogen per carbon). 5) Hydrogen atoms from NADH were also found on the odd-numbered methylene carbon atoms, but the number of incorporated hydrogen atoms was less than expected. The exchange of HB hydrogen of NADH with water catalyzed by enoyl reductase was suspected. 6) The exchange of methylene hydrogen atoms of malonyl-CoA with proton of water was suggested by 13C NMR analysis.
 ...
PMID:Stereochemical studies of hydrogen incorporation from nucleotides with fatty acid synthetase from Brevibacterium ammoniagenes. 2 69

An electrophilous inhibitor, p-(N,N-di-2-chloroethyl)amino-phenylacetic acid (I), specifically disturbs the mechanism of respiration and phosphorylation coupling in mitochondria. I inhibits respiration and ATPase activity in intact mitochondria and does not affect these processes in mitochondria and submitochondrial particles with partially or completely impaired coupling system. The data obtained show that I inhibits protonophoric function of NADH-ferricianide reductase from submitochondrial particles soluble ATPases from bovine heart and Micrococcus lysodeikticus mitochondria adsorded on octane water interface and has no effect on respective enzymes in water solutions. Cation-transferring enzymes are shown to behave with respect to the inhibitor on lipid water interface like respective enzymes in intact mitochondria, while in water solutions they behave like those in systems with the impaired coupling mechanism. Effect of I on protonophoric function of oligomycin-sensitive ATPase and bacteriorhodopsin plaques isolated from Halobacterium halobium is also studied. It is shown that the precence or the absence of I effect is due to a nature of lipid in the enzymatic complex. I is found also to inhibit specifically the transport of Ca2+ from water to octane in the presence of Ca2+-ATP-ase from rabbit sarcoplasmic reticulum.
 ...
PMID:[Mechanism of action of the specific inhibitor of respiration and phosphorylation in mitochondria--n-(N,N-di-2-chlorethyl)aminophenylacetic acid]. 13 99

The mechanism of hydrogen incorporation into fatty acids was investigated with an enzyme preparation from baker's yeast. Fatty acids synthesized from malonyl-CoA and acetyl-CoA in the presence of D2O or stereospecifically deuterium-labeled NADPH were isolated and analyzed by mass chromatography to examine the localization of deuterium atoms in the molecule. The following results were obtained: 1. Hydrogen atoms from water were found on the even-numbered methylene carbon atoms (2-hydrogen atoms per carbon atom). The second hydrogen atom was incorporated as the result of hydrogen exchange phenomenon between the methylene group of malonyl CoA and water. 2. HB hydrogen of NADPH was used for beta-ketoacyl reductase. 3. HB hydrogen of NADPH was also used for enoyl reductase. 4. Hydrogen atoms from HB position of NADPH were found on the odd-numbered methylene carbon atoms (2-hydrogen atoms per carbon atom).
 ...
PMID:Origin of hydrogen atoms in the fatty acids synthesized with yeast fatty acid synthetase. 33 1

Male Wistar rats were fed commercial ration and given whole milk, skim milk, or water to drink. After 3 weeks the control group showed the greatest weight gain. Rats given whole milk had the smallest livers. Serum cholesterol levels were significantly lower in rats fed either whole or skim milk, but other serum lipids were unaffected. Liver triglyceride levels were lowest in the rats on skim milk. Activities of hepatic fatty acid synthetase, hydroxymethyl-glutaryl coenzyme A reductase and cholesterol 7alpha-hydroxylase were similar in the two milk-fed groups and considerably lower than in the controls.
 ...
PMID:Influence of whole or skim milk on cholesterol metabolism in rats. 42 Jan 51

It has been analised cases of toxic methemoglobinemia in newborns and sucklings on patients of children department city hospital Sombor in period from 1968 to 1979. In all patients methemoglobinemia was caused with wellwater containing nitrates. Originate of this state depends on: growth of child because in first few month of life they have immature methemoglobin reductase in erythrocyte, hypovitaminosis C and gastrointestinal disfunction. Diagnosis was based on anamnestical data that was used water from unhygenic well, on cyanosis of various intensity and that have disappeared during the treatment with vitamin C and not give any recurrence later. In last years number of such cases is decreasing because of better suply with proper drinking water. Further decrease can be achieved with health education and prophylactic peroral consumption of vitamin C in predisposing regions.
 ...
PMID:[Toxic methemoglobinemia in newborns and infants]. 55 47

Isolated thylakoid membranes are damaged during freezing in dilute salt solutions, as shown by the inactivation of photochemical thylakoid reactions. After freezing, a number of membrane proteins were found in the particle-free supernatant. Up to 5% of the total membrane protein was solubilized by freezing, and the pattern of released proteins as seen in sodium dodecyl sulfate gel electrophoretograms was influenced by the nature of the solutes present. Membranes protected by sucrose did not release much protein during freezing. Concentrated salt solutions caused protein release also in the absence of freezing. Among the proteins released were ferredoxin--NADP+ reductase, plastocyanin and coupling factor CF1. Subunits of CF1 were found in different proportions in the supernatants of thylakoid suspensions after freezing in the presence of different salts. Cyclic photophosphorylation was largely inactivated before significant protein release could be detected. It is suggested that protein release is the final consequence of the nonspecific suppression of intramembrane ionic interactions by the high ionic strength created in the vicinity of the membranes by the accumulation of salts during slow freezing. Salt effects on water structure and alterations of nonpolar membrane interactions by the incorporation of (protonated) lipophilic anions from organic salts into the membrane phase during freezing may also be involved.
 ...
PMID:Loss of function of biomembranes and solubilization of membrane proteins during freezing. 68 24

Lipid metabolism was studied in experimental uremia. Uremic (U) rats were compared with sham-operated, pair-fed (PF) controls and with ad-lib-fed (AL) controls. In U animals, fasting glucose concentrations were normal, immunoreactive serum insulin (IRI) levels were decreased, and immunoreactive glucagon levels were increased. A significant increase in the serum concentration of all lipid classes was observed: triglycerides were elevated 10-fold above the values in PF and AL controls; phospholipids, twofold; total cholesterol, threefold; and free cholesterol, sixfold. Cholesterol concentration was increased in beta- and pre-beta-lipoproteins and even more so in alpha- and pre-alpha-lipoproteins. There was an increase in the ratio of free cholesterol/total cholesterol. The fatty acid composition of serum lipoproteins was unchanged. Concomitantly, in liver tissue, there was no change in lipid content (triglyceride, cholesterol) and fatty acid composition. These findings argue against glucose- or insulin-mediated changes in hepatic de novo fatty acid synthesis, chain elongation, or poly-desaturation. In U animals, the HMG-CoA-reductase activity of liver microsomes was slightly, but not significantly, reduced as was tritiated water incorporation into cholesterol in isolated perfused liver preparations. In adipose tissue, there was a decrease in triglyceride content. The results provide evidence against insulin-mediated hepatic overproduction as a major cause of hyperlipoproteinemia in this model of experimental renal insufficiency and point to peripheral under-utilization of lipoproteins.
 ...
PMID:Hyperlipoproteinemia in experimental chronic renal insufficiency in the rat. 69 73

The temperature dependence of drug monooxygenation in phenobarbital-induced rat liver microsomes has been investigated. With 7-ethoxycoumarin as a substrate the activity of the microsomes could be measured down to 0 degrees C by the increase in fluorescence of the dealkylated reaction product 7-hydroxycoumarin (umbelliferone). Arrhenius plots of the activities at various temperatures between 0 degrees C and 45 degrees C showed a break in the activation energy around 20 degrees C. Addition of deoxycholate or high concentrations of glycerol, known to solubilize membrane-bound enzymes, abolished the break of the activation energy. Cholesterol, incorporated into the microsomal membrane in amounts equimolar to the microsomal phospholipid content led to a decrease of the activation energy at low temperatures and to an increase at higher temperatures, resulting in a loss of the break. The activity of microsomal NADPH-cytochrome c reductase with the water -soluble electron acceptor dichlorophenolindophenol showed no discontinuity in the Arrhenius plot. In addition the cumene hydroperoxide-mediated and cytochrome P-450-dependent O-dealkylation of 7-ethoxycoumarin proceeded without a break in the activation energy. It is concluded that phospholipid phase transitions affect the electron transfer from the reductase to cytochrome P-450.
 ...
PMID:Membrane effects on drug monooxygenation activity in hepatic microsomes. 81 39


1 2 3 4 5 6 7 8 9 10 Next >>