NADH scientific update |
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J Bioenerg Biomembr. 2006 Oct 13;
Bera T, Nandi N, Sudhahar D, Akbar MA, Sen A, Das P.
Department of Pharmaceutical Technology, Division of Medicinal Biochemistry, Jadavpur University, Kolkata, 700 032, West Bengal, India.
Preliminary evidence on existence of transplasma membrane electron transport in Entamoeba histolytica trophozoites: a key mechanism for maintaining optimal redox balance.
A study on existence of transplasma membrane electron transport in Entamoeba histolytica trophozoites. This study is conducted as a key mechanism for maintaining optimal redox balance. Entamoeba histolytica was verified during the study to check whether it is capable to reduce the oxidized form of alpha-lipoic acid.
Entamoeba histolytica, an amitochondriate parasitic protist, was demonstrated to be capable of reducing the oxidized form of alpha-lipoic acid, a non permeable electron acceptor outside the plasma membrane. This transmembrane reduction of non permeable electron acceptors with redox potentials ranging from -290 mV to +360 mV takes place at neutral pH. The transmembrane reduction of non permeable electron acceptors was not inhibited by mitochondrial electron transport inhibitors such as antimycin A, rotenone, cyanide and azide. However, a clear inhibition with complex III inhibitor, 2-(n-heptyl)-4-hydroxyquinoline-N-oxide; modifiers of sulphydryl groups and inhibitors of glycolysis was revealed. The iron-sulphur centre inhibitor thenoyltrifluoroacetone failed to inhibit the reduction of non permeable electron acceptors whereas capsaicin, an inhibitor of energy coupling NADH oxidase, showed substantial inhibition. p-trifluromethoxychlorophenylhydrazone, a protonophore uncoupler, resulted in the stimulation of alpha-lipoic acid reduction but inhibition in oxygen uptake. Mitochondrial electron transport inhibitors substantially inhibited the oxygen uptake in E. histolytica. Transmembrane reduction of alpha-lipoic acid was strongly stimulated by anaerobiosis and anaerobic stimulation was inhibited by 2-(n-heptyl)-4-hydroxyquinoline-N-oxide. Transmembrane redox system of E. histolytica was also found to be sensitive to UV irradiation. All these findings clearly demonstrate the existence of transplasma membrane electron transport system in E. histolytica and possible involvment of a naphthoquinone coenzyme in transmembrane redox of E. histolytica which is different from that of mammalian host and therefore can provide a novel target for future rational chemotherapeutic drug designing.
Arch Biochem Biophys. 2004 Nov 15;431(2):233-44.
Ainsley Davis C, Crowley LJ, Barber MJ.
Department of Biochemistry and Molecular Biology, College of Medicine, University of South Florida, Tampa, FL 33612, USA.
Cytochrome b(5) reductase: the roles of the recessive congenital methemoglobinemia mutants P144L, L148P, and R159*.
Here the author reports the roles of the recessive congenital methemoglobinemia mutants P144L, L148P, and R159* using Cytochrome b(5) reductase. Cytochrome b(5) reductase is the microsomal forms of the flavoprotein. This disease is directly linked with a specific enzyme deficiency
Recessive congenital methemoglobinemia (RCM, OMIM 250800) arises from defects in either the erythrocytic or microsomal forms of the flavoprotein, cytochrome b(5) reductase (cb(5)r) and was the first disease to be directly associated with a specific enzyme deficiency. Of the 33 verified mutations in cb(5)r that give rise to either the type I (erythrocytic) or type II (generalized) forms of RCM, three of the mutations, corresponding to P144L, L148P, and R159*, are located in a segment of the primary sequence composed of residues G143 to V171 which serves as a "hinge" or "linker" region between the FAD- and NADH-binding lobes of the protein. With the exception of R159*, which produces a truncated non-functional cb(5)r resulting in type II RCM, the type I methemoglobinemias resulting from the P144L or L148P mutations have been proposed to be due to decreased enzyme stability. Utilizing a recombinant form of the rat cb(5)r enzyme, we have generated the P144L, L148P, and P144L/L148P mutants, purified the resulting proteins to homogeneity and characterized their spectroscopic, kinetic, and thermodynamic properties. The three mutant proteins retained full complements of FAD with the P144L and L148P variants being spectroscopically indistinguishable from wild-type cb(5)r. In contrast, kinetic analyses revealed that the P144L, L148P, and P144L/L148P variants retained only 28, 31, and 8% of wild-type NADH:cytochrome b(5) reductase activity, respectively, together with significant alterations in affinity for both NADH and NAD(+). In addition, FAD oxidation-reduction potentials were 32, 19, and 65mV more positive for the mutants than the corresponding FAD/FADH(2) couple in native cb(5)r (E(0')=-272mV). Thermal and proteolytic stability measurements indicated that all three mutants were less stable than the wild-type protein while differential spectroscopy indicated altered pyridine nucleotide binding in all three variants. These results demonstrate that the "hinge" region is important in maintaining the correct orientation of the flavin- and pyridine nucleotide-binding lobes within the protein for efficient electron transfer and that the P144L and L148P mutations disrupt the normal registration of the FAD- and NADH-binding lobes resulting in altered affinities for both the physiological reducing substrate, NADH and its product, NAD(+).
Biophys Chem. 2005 Apr 1;115(2-3):219-24. Epub 2004 Dec 24.
Martinez-Julvez M, Tejero J, R Peregrina J, Nogues I, Frago S, Gomez-Moreno C, Medina M.
Departamento de Bioquimica y Biologia Molecular y Celular and Institute of Biocomputation and Physics of Complex Systems (BiFi), Facultad de Ciencias, Universidad de Zaragoza, 50009 Zaragoza, Spain.
Towards a new interaction enzyme:coenzyme.
An evaluation on a new interaction enzyme named coenzyme. The combined effect of both NAD(+)/H and NADP(+)/H were evaluated during the study. The researchers filed to discriminate between both coenzymes.
Ferredoxin-NADP(+) reductase catalyses NADP(+) reduction, being specific for NADP(+)/H. To understand coenzyme specificity determinants and coenzyme specificity reversion, mutations at the NADP(+)/H pyrophosphate binding and of the C-terminal regions have been simultaneously introduced in Anabaena FNR. The T155G/A160T/L263P/Y303S mutant was produced. The mutated enzyme presents similar k(cat) values for NADPH and NADH, around 2.5 times slower than that reported for WT FNR with NADPH. Its K(m) value for NADH decreased 20-fold with regard to WT FNR, whereas the K(m) for NADPH remains similar. The combined effect is a much higher catalytic efficiency for NAD(+)/H, with a minor decrease of that for NADP(+)/H. In the mutated enzyme, the specificity for NADPH versus NADH has been decreased from 67,500 times to only 12 times, being unable to discriminate between both coenzymes. Additionally, giving the role stated for the C-terminal Tyr in FNR, its role in the energetics of the FAD binding has been analysed.
Free Radic Biol Med. 2005 Jun 1;38(11):1484-90.
Olek RA, Antosiewicz J, Popinigis J, Gabbianelli R, Fedeli D, Falcioni G.
Department of Bioenergetics, Jedrzej Sniadecki University School of Physical Education, Wiejska 1, 80-336 Gdansk, Poland.
Pyruvate but not lactate prevents NADH-induced myoglobin oxidation.
A recent study proved that pyruvate prevents NADH-induced myoglobin oxidation. But lactate is not effective in preventing NADH-induced myoglobin oxidation. The influence of NADH on the redox state of myoglobin was tested during the test.
In this work, we investigated the influence of NADH on the redox state of myoglobin and the roles of pyruvate and lactate in this process. NADH increased the autoxidation rate of myoglobin. Both a drop in pH and partial deoxygenation markedly stimulated the autoxidation process and the influence of NADH. A correlation between met-Mb formation rate and NADH oxidation rate was always observed. The increased rate of Mb autoxidation caused by NADH was inhibited by catalase and pyruvate but not by l-lactate. The antioxidant activity versus H(2)O(2) of both pyruvate and lactate was evidenced by chemiluminescence experiments. The antioxidant activity of lactate disappeared completely in the presence of myoglobin or apo-myoglobin, whereas it was only reduced for pyruvate. These results could be of interest in preventing autoxidation of myoglobin that can contribute to ischemia-reperfusion injury during infarction or high-intensity exercise.
Mech Ageing Dev. 2005 Jun-Jul;126(6-7):705-9. Epub 2005 Feb 12.
Kokaze A, Ishikawa M, Matsunaga N, Yoshida M, Makita R, Satoh M, Teruya K, Sekiguchi K, Masuda Y, Harada M, Uchida Y, Takashima Y.
Department of Public Health, Kyorin University School of Medicine, 6-20-2 Shinkawa, Mitaka-shi, Tokyo 181-8611, Japan.
Longevity-associated NADH dehydrogenase subunit-2 polymorphism and serum electrolyte levels in middle-aged obese Japanese men.
Report of a recent study on longevity-associated NADH dehydrogenase subunit-2 polymorphism and serum electrolyte levels in middle-aged obese Japanese men. Some time it may influence serum electrolyte levels in middle-aged obese Japanese men. An association study was conducted in 321 healthy middle-aged Japanese men.
Mitochondrial DNA 5178 cytosine/adenine polymorphism, which is also called NADH dehydrogenase subunit-2 237 leucine/methionine (ND2-237 Leu/Met) polymorphism is associated with Japanese longevity. This polymorphism is widely associated with blood pressure, serum lipid levels, hematological parameters, intraocular pressure, and serum protein fraction levels. However, there have been no reports on the association between ND2-237 Leu/Met polymorphism and serum electrolyte levels. To investigate this relationship, we performed an association study in 321 healthy middle-aged Japanese men. Crude data showed that serum sodium levels and serum chloride levels were significantly lower in men with ND2-237 Met than in those with ND2-237 Leu (P=0.021 and 0.003, respectively). Cigarette consumption and body mass index were significantly and positively associated with serum chloride levels (P=0.002 and 0.008, respectively) and hemoglobin levels were significantly and negatively associated with them (P=0.007) in ND2-237 Leu genotypic men. In men with ND2-237 Met, only hemoglobin levels were significantly and negatively associated with serum chloride levels (P=0.025). After adjusting for covariates, only in male obese (body mass index>/=25) subjects, serum sodium and chloride levels remained significantly lower, and serum calcium levels appeared to be significantly higher in ND2-237 Met than in ND2-237 Leu (P=0.013, <0.001, and 0.046, respectively). Longevity-associated NADH dehydrogenase subunit-2 polymorphism may influence serum electrolyte levels in middle-aged obese Japanese men.
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Drug category:Antioxidants and Vitamines
 NADH scientific update
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