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Apart from demonstrating the interaction behavior of malondialdehyde (MDA)with [Na.sup.+]/[K.sup.+]-ATPase using in silico, the current study aims to investigate the effect of rheumatoid arthritis-related oxidative stress on [Na.sup.+]/[K.sup.+]-ATPase activity that is present in the erythrocyte cell membrane, which is rich in proteins vulnerable to damage from MDA and other free radicals. The target population of this study consists of 28 rheumatoid arthritis patients and 20 healthy volunteers whose MDA levels and [Na.sup.+]/[K.sup.+]-ATPase activity were determined. It was shown that MDA levels of rheumatoid arthritis patients increased (p < 0.001) and their [Na.sup.+]/[K.sup.+]-ATPase activity noticeably decreased when compared to those of healthy individuals. Also, according to this in silico modeling, MDA decreased [Na.sup.+]/[K.sup.+]-ATPase activity in line with the correlation analyses. Consequently, while elevated levels of MDA in the rheumatoid arthritis group were suggestive of oxidative stress, a decreased [Na.sup.+]/[K.sup.+]-ATPase-activity led us to speculate that the cellular membrane had sustained injury. Therefore, our results could be useful in explaining how MDA affects [Na.sup.+]/[K.sup.+]-ATPase activity in the interior of a specific molecular pathway. Key words: [Na.sup.+]/[K.sup.+]-ATPase activity, rheumatoid arthritis, lipid peroxidation, negative binding energy, molecular docking Outre la demonstration in silico d'un comportement interactif du malondialdehyde avec la [Na.sup.+]/[K.sup.+]-ATPase, la presente etude portait sur l'effet du stress oxydatif lie a la polyarthrite rhumatoide (PAR) sur l'activite de la [Na.sup.+]/[K.sup.+]-ATPase qui est present dans la membrane des erythrocytes, qui est riche en proteines vulnerables aux dommages causes par le malondialdehyde et autres radicaux libres. La population cible de cette etude etait constituee de 28 patients atteints de PAR et de 20 volontaires sains chez qui nous avons etabli les taux de malondialdehyde et l'activite de la [Na.sup.+]/[K.sup.+]-ATPase. Nous avons observe que chez les patients atteints de PAR, les taux de malondialdehyde etaient plus eleves (p < 0,001), et l'activite de la [Na.sup.+]/[K.sup.+]-ATPase etait nettement moins elevee que chez les sujets en bonne sante. De plus, selon les donnees in silico, le malondialdehyde entrainait une diminution de l'activite de la [Na.sup.+]/[K.sup.+]-ATPase correspondant aux analyses de correlation. Consequemment, tandis que l'augmentation des taux de malondialdehyde dans le groupe PAR etait suggestive d'un stress oxydatif, la diminution de l'activite de la [Na.sup.+]/[K.sup.+]-ATPase nous a amenes a speculer que la membrane cellulaire avait subi des dommages. Par consequent, nos resultats pourraient etre utiles pour expliquer comment le malondialdehyde affecte l'activite de la [Na.sup.+]/[K.sup.+]-ATPase au sein d'une voie de signalisation moleculaire specifique. [Traduit par la Redaction] Mots-cles : : activite de la [Na.sup.+]/[K.sup.+]-ATPase, polyarthrite rhumatoide, peroxydation lipidique, energie de liaison negative, arrimage moleculaire, 1. Introduction Reactive oxygen species (ROS) are described as partially reduced metabolites of oxygen capable of making strong oxidization. ROS are also capable of initiating cellular damage as highly reactive [...]

ABSTRACT Background: Chronic hyperglycemia during diabetes is associated with altered cognitive function. Cinnamaldehyde showed to have many pharmacological activities indicating anti-diabetic, cognitive enhancer, antiinflammatory etc. In the present study, we [...]

Methylglyoxal (MG), a reactive α, β-dicarbonyl ketoaldehyde, is unavoidable by-product of several metabolic pathways, it has long been considered as cytotoxin at high concentration, but now is emerging signal molecule function at low concentration in plants. Thus, MG homeostasis in plant cells is very important to exert its physiological function. Glyoxalase system, mainly including glyoxalase I and glyoxalase II, is the major regulator of MG homeostasis in plants. Recent years, research on MG and its detoxification system glyoxalase has attracted much attention in plant biology. Based on the current progress on MG and glyoxalase system, in this review, MG biosynthesis and degradation; determination of MG; MG as signal iniator crosstalk with [Ca.sup.2+], reactive oxygen species and abscisic acid; satl, heavy metal, drought, cold and heat tolerance involved in MG and glyoxalase system; stomatal movement; seed germiantion; and cell division and organ differentiation, were summarized. Meanwhile, research direction in the future was presented. Keywords Antioxidant system * Glyoxalase system * Methylglyoxal * Signal crosstalk * Stress tolerance, Introduction Methylglyoxal (MG; CH3COCHO) which is a typical oxygenated short aldehyde is a by-product of several metabolic pathways, including glycolysis, photosynthesis, lipid peroxidation and oxidative degradation of glucose and glycated [...]

Haematopoietic stem cells renew blood. Accumulation of DNA damage in these cells promotes their decline, while misrepair of this damage initiates malignancies. Here we describe the features and mutational landscape of DNA damage caused by acetaldehyde, an endogenous and alcohol-derived metabolite. This damage results in DNA double-stranded breaks that, despite stimulating recombination repair, also cause chromosome rearrangements. We combined transplantation of single haematopoietic stem cells with whole-genome sequencing to show that this damage occurs in stem cells, leading to deletions and rearrangements that are indicative of microhomology-mediated end-joining repair. Moreover, deletion of p53 completely rescues the survival of aldehyde-stressed and mutated haematopoietic stem cells, but does not change the pattern or the intensity of genome instability within individual stem cells. These findings characterize the mutation of the stem-cell genome by an alcohol-derived and endogenous source of DNA damage. Furthermore, we identify how the choice of DNA-repair pathway and a stringent p53 response limit the transmission of aldehyde-induced mutations in stem cells., Author(s): Juan I. Garaycoechea [1]; Gerry P. Crossan [1]; Frdric Langevin [1]; Lee Mulderrig [1]; Sandra Louzada [2]; Fentang Yang [2]; Guillaume Guilbaud [1]; Naomi Park [2]; Sophie Roerink [2]; [...]

Adiabatic differential scanning calorimetry was used to investigate the effect of [NADP.sup.+] on the irreversible thermal denaturation of the nonphosphorylating glyceraldehyde-3-phosphate dehydrogenase (GAPN) from Streptococcus mutans. The GAPN-[NADP.sup.+] binary complex showed a strongly decreased thermal stability, with a difference of about 20 °C between the temperatures of the thermal transition peak maxima of the complex and the free protein. This finding was similar to the previously described thermal destabilization of GAPN upon binding of inorganic phosphate to the substrate binding site and can be interpreted as the shift of the equilibrium between 2 conformers of tetrameric GAPN upon addition of the coenzyme. Single amino acid substitution, known to abolish the [NADP.sup.+] binding, cancelled the calorimetric effect of the coenzyme. GAPN thermal inactivation was considerably decelerated in the presence of [NADP.sup.+] showing that the apparent change in stability of the active centre can be the opposite to that of the whole protein molecule. [NADP.sup.+] could also reactivate the inactive [GAPN.sup.*] species, obtained by the heating of the apoenzyme below the thermal denaturation transition temperature. These effects may reflect a mechanism that provides GAPN the sufficient flexibility for the earlier observed profound active site reorganizations required during the catalytic cycle. The elevated thermal stability of the apoenzyme may, in turn, be important for maintaining a constant level of active GAPNan enzyme that is known to be crucial for the effective supply of the reducing equivalents in S. mutans and its ability to grow under aerobic conditions. Key words: dehydrogenase, differential scanning calorimetry, GAPN, [NADP.sup.+]. La calorimetrie differentielle a balayage adiabatique a ete utilisee afin d'examiner l'effet du [NADP.sup.+] sur la denaturation thermique irreversible de la glyceraldehyde-3-phosphate deshydrogenase non phosphorylante (GAPN) de Streptococcus mutans.Le complexe binaire GAPN-[NADP.sup.+] presente une stabilite thermique fortement diminuee, avec une difference d'environ 20 °C entre les temperatures maximales des pics de transition thermique comparativement a la proteine libre. Ce resultat est similaire a ce qui avait ete precedemment decrit sur la destabilisation thermique de la GAPN consecutive a la liaison d'un phosphate inorganique au site de liaison du substrat. Ceci peut etre interprete comme un deplacement de l'equilibre entre deux conformeres de la GAPN tetramerique a la suite de la liaison du coenzyme. Une substitution simple d'un acide amine connue pour abolir la liaison du [NADP.sup.+] annule l'effet calorimetrique du coenzyme. Fait remarquable, l'inactivation thermique de la GAPN est considerablement ralentie en presence de [NADP.sup.+], montrant que le changement apparent de stabilite du centre actif peut resulter en des effets opposes a ceux de la proteine entiere. Le [NADP.sup.+] peut aussi reactiver la [GAPN.sup.*] inactive obtenue par chauffage de l'apoenzyme a une temperature inferieure a la temperature de transition thermique. Ces effets pourraient refleter un mecanisme qui donne a la GAPN la flexibilite necessaire aux importantes reorganisations conformationnelles observees precedemment dans le site actif, requises durant le cycle catalytique. La stabilite thermique elevee de l'apoenzyme pourrait, en retour, constituer un element important pour le maintien d'un niveau constant de GAPN active--une enzyme essentielle a la production d'equivalents reducteurs chez S. mutans et a sa capacite a croitre en conditions aerobies. [Traduit par la Redaction] Mots-cles: deshydrogenase, calorimetrie differentielle a balayage, GAPN, [NADP.sup.+]., Introduction Nonphosphorylating glyceraldehyde-3-phosphate dehydrogenase (GAPN; EC 1.2.1.9) catalyzes the irreversible NADP (+)-dependent oxidation of D-glyceraldehyde-3-phosphate (D-GAP) into 3-phosphoglycerate. GAPN gene sequences are nonrelated to that of phosphorylating GAP dehydrogenase and [...]

ARTICLE INFO Keywords: Phosphatidylserine Trans-cinnamaldehyde Calcium Cell volume Eryptosis ABSTRACT Trans-cinnamaldehyde, a component of leaves from Cinnamomum osmophloeum kaneh, has been shown to counteract tumor growth. The substance exerts its [...]

Byline: Sridevi. Chigurupati, Sohrab. Shaikh, Jahidul. Mohammad, Kesavanarayanan. Selvarajan, Appala. Nemala, Chu. Khaw, Chun. Teoh, Ting. Kee Objectives: In this study, three (CS-1 to CS-3) azomethine derivatives of cinnamaldehyde were [...]

Introduction: Osteoporosis is a multifactorial genetic disease which greatly increases the risk of bone fracture in elderly persons. Methods: Four hundred and three recipients of a community health screening program were examined for the presence/absence of osteoporosis and 11 kinds of gene polymorphisms as a means of determining the relation between these gene polymorphisms and osteoporosis. The gene polymorphisms screened were: alcohol sensitivity-associated polymorphisms of alcohol dehydrogenase (ADH2) Arg47His, aldehyde dehydrogenase (ALDH2) Glu487Lys, smoking sensitivity-associated polymorphisms of glutathione S transferase (GST) M1, (GST)T1, NAD(P)H quinone oxidoreductase 1 (NQO1) C609T, inflammation-associated polymorphisms of interleukin-1[beta] (IL-1B)T-31C, tumor necrosis factor [alpha] (TNF-[alpha]) T-1031C, endothelial constitutive nitric oxide synthase (ecNOS) Glu298Asp, longevity-associated polymorphism of mitochondrial DNA (mtDNA) 5178 A/C, allergy-associated polymorphism of interleukin-4 (IL-4), and immunity-associated polymorphism of CD14. Results: A significant association was found between the ALDH2Glu478Lys gene polymorphisms and osteoporosis. In the osteoporosis group of patients, a significant difference was noted between the Lys/Lys group and the group comprising Glu/Lys and Glu/ Glu groups (namely, the genotypes including Glu alleles). In the Lys/Lys group, after age, sex, BMI, smoking history and alcohol consumption history had been adjusted for, the morbidity rate was significantly elevated [odds ratio (OR): 3.33; 95% confidence interval (95% CI): 1.28-8.71; p=0.014], and the effect was even more evident in the sub-group of women with osteoporosis (OR: 4.31; 95% CI: 1.24-14.92; p=0.021). Conclusions: The present results suggest that active prophylactic interventions such as dietary, exercise, and pharmacological therapies should be offered to non-carriers of the Glu allele (Lys/Lys). Keywords Japanese elderly people * Osteoporosis ALDH2 polymorphism

WOR5 is the fifth and last member of the family of tungsten-containing oxidoreductases purified from the hypertbermophilic archaeon Pyrococcus furiosus. It is a homodimeric protein (subunit, 65 kDa) that contains one [4Fe-4S] cluster and one tungstobispterin cofactor per subunit. It has a broad substrate specificity with a high affinity for several substituted and nonsubstituted aliphatic and aromatic aldehydes with various chain lengths. The highest catalytic efficiency of WOR5 is found for the oxidation of hexanal ([V.sub.max] = 15.6 U/mg, [K.sub.m] = 0.18 mM at 60[degrees]C). Hexanal-incubated enzyme exhibits S = 1/2 electron paramagnetic resonance signals from [[4Fe-4S].sup.1+] (g values of 2.08, 1.93, and 1.87) and [W.sup.5+] (g values of 1.977, 1.906, and 1.855). Cyclic voltammetry of ferredoxin and WOR5 on an activated glassy carbon electrode shows a catalytic wave upon addition of hexanal, suggesting that ferredoxin can be a physiological redox partner. The combination of WOR5, formaldehyde oxidoreductase, and aldehyde oxidoreductase forms an efficient catalyst for the oxidation of a broad range of aldehydes in P. furiosus.

Byline: Anil Dahuja (1), T.R. Madaan (1) Keywords: Carbonyl value; Hexanal; Hydroperoxidation; Lipoxygenase activity; Malondialdehyde; Soybeans; Thiobarbituric acid (TBA) number Abstract: Production of hydroperoxides and volatile aldehydes, having low olfactory thresholds by lipoxygenase (LOX) action, is an importantproblem in the effective use of soybeans as food ingredients. In this study, researchers examined sixteen soybean varieties for LOX activity, thiobarbituric acid (TBA) number, a measure of lipid peroxides, and carbonyl value, an index of ketone compounds, responsible for off-flavor. Among the soybeans tested, PK416 and JS7015 had the lowest levels of LOX activity, TBA number as well as carbonyl value. The highest value for these parameters were observed in Pb-1 and Bragg. These results suggest that PK416 and JS7015 could be excellent soybean sources for making good quality soy products. Author Affiliation: (1) Division of Biochemistry, Indian Agricultural Research Institute, New Delhi-110012, India Article History: Registration Date: 23/12/2004

Research has been conducted on the role of pduA genes in polyhedral organelle formation by Salmonella enterica. Results indicate that S. enterica organelles are not involved in 1,2-propanedienol concentrating but are important for moderating the aldehyde toxicity.

Byline: Mufide. Oncel, Aysel. Kiyici, Murat. Oncel, Guven. Sadi, Emel. Sahin, Bahattin. Adam Background: Videothoracoscopic surgery leads to general organ hypoperfusion by reducing mean arterial pressure, systemic vascular resistance, and [...]

The incidence of skin sensitization, respiratory sensitization and allergic blepharoconjunctivitis among workers routinely exposed to glutaraldehyde for several years was investigated. The results showed that the incidence of sensitization was negligible, with most cases being attributable to chemicals other than glutaraldehyde.