Reconstructing a chloride-binding site in a bacterial neurotransmitter transporter homologue

In ion-coupled transport proteins, occupation of selective ion-binding sites is required to trigger conformational changes that lead to substrate translocation. Neurotransmitter transporters, targets of abused and therapeutic drugs, require Na(+) and Cl(-) for function. We recently proposed a chloride-binding site in these proteins not present in Cl(-)-independent prokaryotic homologues. Here we describe conversion of the Cl(-)-independent prokaryotic tryptophan transporter TnaT to a fully functional Cl(-)-dependent form by a single point mutation, D268S. Mutations in TnaT-D268S, in wild type TnaT and in serotonin transporter provide direct evidence for the involvement of each of the proposed residues in Cl(-) coordination. In both SERT and TnaT-D268S, Cl(-) and Na(+) mutually increased each other's potency, consistent with electrostatic interaction through adjacent binding sites. These studies establish the site where Cl(-) binds to trigger conformational change during neurotransmitter transport.     

Tetra primer ARMS-PCR relates folate/homocysteine pathway genes and ACE gene polymorphism with coronary artery disease

Cardiovascular disorders and coronary artery disease (CAD) are significant contributors to morbidity and mortality in heart patients. As genes of the folate/homocysteine pathway have been linked with the vascular disease, we investigated association of these gene polymorphisms with CAD/myocardial infarction (MI) using the novel approach of tetraprimer ARMS-PCR. A total of 230 participants (129 MI cases, 101 normal subjects) were recruited. We genotyped rs1801133 and rs1801131 SNPs in 5'10' methylenetetrahydrofolate reductase (MTHFR), rs1805087 SNP in 5' methyltetrahydrofolate homocysteine methyltransferase (MTR), rs662 SNP in paroxanse1 (PON1), and rs5742905 polymorphism in cystathionine beta synthase (CBS). Angiotensin converting enzyme (ACE) insertion/deletion polymorphism was detected through conventional PCR. Covariates included blood pressure, fasting blood sugar, serum cholesterol, and creatinine concentrations. Our results showed allele frequencies at rs1801133, rs1801131, rs1805087 and the ACE insertion/deletion (I/D) polymorphism varied between cases and controls. Logistic regression, after adjusting for covariates, demonstrated significant associations of rs1801133 and rs1805087 with CAD in the additive, dominant, and genotype model. In contrast, ACE I/D polymorphism was significantly related with CAD where recessive model was applied. Gene-gene interaction against the disease status revealed two polymorphism groups: rs1801133, rs662, and rs1805087; and rs1801131, rs662, and ACE I/D. Only the latter interaction maintained significance after adjusted for covariates. Our study concludes that folate pathway variants exert contributory influence on susceptibility to CAD. We further suggest that tetraprimer ARMS-PCR successfully resolves the genotypes in selected samples and might prove to be a superior technique compared to the conventional approach.     

Modification of cellulosic fabric using polyvinyl alcohol—Part-I: Physicochemical properties

A series of poly(vinyl alcohol) of different commercial grades were prepared and applied onto the surfaces of cotton and blends of cotton/polyester fibers. The molecular structure was confirmed using Fourier Transform Infrared spectroscopy. Physicochemical properties such as viscosity and solid contents (%) were determined and discussed. Factors affecting the performance properties of the finished substrate such as post-treatment with poly(vinyl alcohol) of different grades, concentration and dilutions were studied. Fixation of the poly(vinyl alcohol) onto/or within the cellulose structure is accompanied by the formation of semi-inter-penetrated network structure thereby enhancing the association as well as providing very high stiffness. The results revealed that applications of poly(vinyl alcohol) on the textile fabrics in the finishing processes enables to enhance the stiffness as well as helps to improve its pilling resistance.     

Stromal-derived factor-1 (SDF-1) expression during early chick development

Cell migration plays a fundamental role in a wide variety of biological processes including development, tissue repair and disease. These processes depend on directed cell migration along and through cell layers. Chemokines are small secretory proteins that exert their effects by activating a family of G-protein coupled receptors and have been shown to play numerous fundamental roles in the control of physiological and pathological processes during development and in adult tissues, respectively. Stromal-derived factor-1 (SDF-1/CXCL12), a ligand of the chemokine receptor, CXCR4, is involved in providing cells with directional cues as well as in controlling their proliferation and differentiation. Here we studied the expression pattern of SDF-1 in the developing chick embryo. We could detect a specific expression of SDF-1 in the ectoderm, the sclerotome, the intersomitic spaces and the developing limbs. The expression domains of SDF-1 reflect its role in somitic precursor migration and vessel formation in the limbs.     

Dietary Flaxseed Oil Supplementation Mitigates the Effect of Lead on the Enzymes of Carbohydrate Metabolism, Brush Border Membrane, and Oxidative Stress in Rat Kidney Tissues

Lead is a heavy metal widely distributed in the environment. Lead is a ubiquitous environmental toxin that is capable of causing numerous acute and chronic illnesses. Human and animal exposure demonstrates that lead is nephrotoxic. However, attempts to reduce lead-induced nephrotoxicity were not found suitable for clinical use. Recently, flaxseed oil (FXO), a rich source of ω-3 fatty acids and lignans, has been shown to prevent/reduce the progression of certain types of cardiovascular and renal disorders. In view of this, the present study investigates the protective effect of FXO on lead acetate (PbAc)-induced renal damage. Rats were pre-fed normal diet and the diet rich in FXO for 14 days, and then, four doses of lead acetate (25 mg/kg body weight) were administered intraperitoneally while still on diet. Various serum parameters, enzymes of carbohydrate metabolism, brush border membrane (BBM), and oxidative stress were analyzed in rat kidney. PbAc nephrotoxicity was characterized by increased serum creatinine and blood urea nitrogen. PbAc increased the activities of lactate dehydrogenase and NADP-malic enzyme, whereas it decreased malate and glucose-6-phosphate dehydrogenase, glucose-6-phosphatase, fructose-1, 6-bisphosphatase, and BBM enzyme activities. PbAc caused oxidant/antioxidant imbalances as reflected by increased lipid peroxidation and decreased activities of superoxide dismutase, glutathione peroxidase, and catalase. In contrast, FXO alone enhanced the enzyme activities of carbohydrate metabolism, BBM, and antioxidant defense system. FXO feeding to PbAc-treated rats markedly enhanced resistance to PbAc-elicited deleterious effects. In conclusion, dietary FXO supplementation ameliorated PbAc-induced specific metabolic alterations and oxidative damage by empowering antioxidant defense mechanism and improving BBM integrity and energy metabolism.     

Binding of antibromelain monomeric Fab' improves the stability of stem bromelain against inactivation

Antienzyme polyclonal antibodies against stem bromelain were raised in male albino rabbits and the Fab' monomers isolated from the IgG of the immune sera. Incubation of bromelain with the Fab' resulted in binding and gel filtration of the resulting complex suggested a 1:1 stoichiometry. Complexing with the Fab' resulted in significant stabilization of bromelain against thermal inactivation and alkaline pH.     

Fulvic Acid Prevents Chromium-induced Morphological,Photosynthetic, and Oxidative Alterations in Wheat Irrigated with Tannery Waste Water

Journal of Plant Growth Regulation - Rapid industrialization is potentially contaminating the environment. Tannery is one of the industries producing very high amount of effluents, having a...