the equilibrium constant of adduct formation between some triorganotin chloride of the type r3sncl (r=c6h5, p-ch3c6h4, n-ch3)ch2)3, c6h5-ch2 and lewis bases cl¯, br¯, and i¯, were measured in 50% v/v ethanol-water solvent spectrophotometrically. the average equilibrium constant values for the systems studied shows the following acceptor trend of tin(iv) in the triorganotin chlorides: p-tolyl > ...

Proton transfer in polymer electrolyte membrane is an essential mechanism fuel cell (PEMFC). The development of PEM mostly relies on modification with proton conductive species followed by casting. This brings the random existence to result a limit conductivity. present work proposes alignment species, i.e., donor and acceptor chains, through surface-initiated polymerization so that proceeds ef...

Escherichia coli lipoic acid ligase (LplA) catalyzes ATP-dependent covalent ligation of lipoic acid onto specific lysine side chains of three acceptor proteins involved in oxidative metabolism. Our lab has shown that LplA and engineered mutants can ligate useful small-molecule probes such as alkyl azides ( Nat. Biotechnol. 2007 , 25 , 1483 - 1487 ) and photo-cross-linkers ( Angew. Chem., Int. E...

Sialyltransferases are enzymes responsible for the important sialylation of glycoconjugates. Since crystal structures are not available, other tools are needed to study enzymatic mechanisms. As a model, we used human alpha2,6-sialyltransferase. A putative acceptor-binding domain containing the small and the very small sialyl motifs was randomly mutated. This resulted in enzymes with altered enz...

γ-Glutamyl transpeptidase (GGT) is a two-substrate enzyme that plays a central role in glutathione metabolism and is a potential target for drug design. GGT catalyzes the cleavage of γ-glutamyl donor substrates and the transfer of the γ-glutamyl moiety to an amine of an acceptor substrate or water. Although structures of bacterial GGT have revealed details of the protein-ligand interactions at ...

2-(Thiophen-2-yl)thiazole was introduced as a π-bridge into diethylamino coumarin and novel coumarin sensitizers were synthesized with cyanoacrylic acid or rhodanine acetic acid as electron acceptor. Their light-harvesting capabilities and photovoltaic performance were investigated and compared with those of a similar sensitizer bearing a phenylthiophene bridge. Replacement of benzene in the π-...

objective: methylmalonic acidura (mma) is a rare autosomal recessive inborn error of metabolism. in this study we present a novel nucleotide change in the mutase (mut) gene of two unrelated iranian pedigrees and introduce the methods used for its functional analysis. materials and methods: two probands with definite diagnosis of mma and a common novel variant in the mut were included in a descr...

In the presence of N(alpha),N(epsilon)-diacetyl-L-Lys-D-Ala-D-Ala as donor, and either D-[(14)C]alanine, [(14)C]-glycine, or meso-[(3)H]diaminopimelic acid as acceptor, the DD carboxypeptidases from Streptomyces R61 and R39 catalyze a transpeptidation reaction with the release of terminal D-alanine from the donor and the formation of either N(alpha),N(epsilon)-diacetyl-L-Lys-D-Ala-D-[(14)C]Ala,...

We have characterized the size, intensity, density, and distribution of charge-transfer (CT) excitons as a function acceptor–donor architecture prototypical organic interfaces. This characterization was done by computational analysis 17 models varying numbers, positions, orientations donor acceptor molecules. The models’ building blocks were phenyl-C61-butyric acid methyl ester (PCBM) fullerene...