nanofiltration-based separation processes have found diverse applications in industrial and environmentalproblems recently, due to several advantages such as lower energy requirement and elevated flux ratescompared with their reverse osmosis (ro) counterparts. several attempts have been made for modellingnf-based separation processes ranging from rigorous space-charge approaches to simpler irre...

Here we describe the role of charged amino acids at the catalytic sites of Escherichia coli ATP synthase. There are four positively charged and four negatively charged residues in the vicinity of of E. coli ATP synthase catalytic sites. Positive charges are contributed by three arginine and one lysine, while negative charges are contributed by two aspartic acid and two glutamic acid residues. R...

To ensure high fidelity in translation, many aminoacyl-tRNA synthetases, enzymes responsible for attaching specific amino acids to cognate tRNAs, require proof-reading mechanisms. Most bacterial prolyl-tRNA synthetases (ProRSs) misactivate alanine and employ a post-transfer editing mechanism to hydrolyze Ala-tRNA(Pro). This reaction occurs in a second catalytic site (INS) that is distinct from ...

Using Gaussian 03, software the thermodynamic functions such as Gibbs free energy, G, Enthalpy, H, and Entropy, S, of Alanine and Valine amino acids were theoretically studied at different solvents. First, the Density Functional Theory (B3LYP) level with 3-21G, 6-31G and 6-31+G basis sets were employed to optimization of isolated Alanine and Valine amino acids in the gas phase. Moreover, Vib...

The non-photosynthetic plastid - or apicoplast - of Toxoplasma gondii and other apicomplexan parasites is an essential organelle and promising drug target. Most apicoplast proteins are encoded in the nucleus and targeted into the organelle through the apicoplast's four membranes courtesy of a bipartite N-terminal leader sequence comprising of an endomembrane signal peptide followed by a plastid...

Mutations of positively charged amino acids in the S4 transmembrane segment of a voltage-gated ion channel form ion-conducting pathways through the voltage-sensing domain, named ω-current. Here, we used structure modeling and MD simulations to predict pathogenic ω-currents in CaV1.1 and CaV1.3 Ca2+ channels bearing several S4 charge mutations. Our modeling predicts that mutations of CaV1.1-R1 (...

Tight junctions (TJ) regulate paracellular ionic charge selectivity and conductance across epithelial tissues and cell lines. These properties vary among epithelia, and recent evidence implicates the claudins, a family of TJ transmembrane proteins, as important determinants of both characteristics. To test the hypothesis that each claudin contributes a characteristic charge discrimination to th...