The beta-N-acetylglucosaminidase of Escherichia coli was found to have a novel specificity and to be encoded by a gene (nagZ) that maps at 25.1 min. It corresponds to an open reading frame, ycfO, whose predicted amino acid sequence is 57% identical to that of Vibrio furnissii ExoII. NagZ hydrolyzes the beta-1,4 glycosidic bond between N-acetylglucosamine and anhydro-N-acetylmuramic acid in cell...

Two known C-glycosylflavones, swertisin and embinoidin, were isolated from the leaves of Anthurium aripoense, and characterized by room temperature 1D and 2D NMR experiments. At this temperature, the ¹H- and ¹³C-NMR spectra of these C-glycosylflavones revealed doubling of signals, which suggested the presence of two rotamers in solution. Variable-temperature (VT) ¹H-NMR studies supported this h...

The 2.0 A crystal structure has been determined for Escherichia coli uridine phosphorylase (UP), an essential enzyme in nucleotide biosynthesis that catalyzes the phosphorolytic cleavage of the C-N glycosidic bond of uridine to ribose-1-phosphate and uracil. The structure determination of two independent monomers in the asymmetric unit revealed the residue composition and atomic details of the ...

DNA glycosylase AlkD excises N7-methylguanine (7mG) by a unique but unknown mechanism, in which the damaged nucleotide is positioned away from the protein and the phosphate backbone is distorted. Here, we show by methylphosphonate substitution that a phosphate proximal to the lesion has a significant effect on the rate enhancement of 7mG depurination by the enzyme. Thus, instead of a convention...

This study aims to modeling the membrane structure of chitosan containing nickel metal and determine adsorption energy gap molecular metal. The was carried out using a computer Avogadro software analyzed with GaussView 6 software. results shape optimization Density Functional Theory (DFT) method basis set B3LYP/LanL2DZ were total chitosan-Ni compound. analysis revealed interaction between Ni. D...

Abstract Maize straw, an abundant agricultural residue, has potential as eco-friendly resource. The aim of this study was to investigate the structure and effect on Bifidobacterium longum exopolysaccharide produced by Weissella cibaria using maize straw a carbon source. In work, exopolysaccharide-producing strain isolated from vegetable juice, which identified W. cibaria. Our results demonstrat...

2',3'-Lyxoanhydrothymidine (LAT), a conformationally restricted inhibitor of retroviral reverse transcriptases, has been studied by X-ray analysis. The unit cell contains two crystallographically independent molecules A and B. Their sugar moieties have an identical structure: an 04'-endo pucker of the furanose cycle and a trans conformation about the exocyclic C4'-C5' bond. The conformations of...

A soil amoeba (Hartmannella glebae), when grown in conjunction with Enterobacter aerogenes and Alcaligenes faecalis, produced two enzymes. Enzyme I was purified by gel filtration on Sephadex G-100 and chromatography on diethylaminoethyl-cellulose. It is a basic protein. The analysis of the enzymic digest of the cell walls of Micrococcus lysodeikticus after reduction and acid hydrolysis showed t...

A flexible and short synthesis of sulfonamide-bridged di-, tri-, tetra-, and octasaccharide glycomimetics was accomplished by reaction of glycosyl thioacetates with amino sugar substrates. The chemistry to incorporate the sulfonamide linker in place of a native O-glycosidic bond was broadly scoped, allowing access to head-to-head (1↔1) and head-to-tail (1→2), (1→3), (1→4), and (1→6) sulfonamide...

A general scheme for the synthesis of C8-arylpurine phosphoramidites has been developed. C8-Arylation of C8-bromo-2'-deoxyguanosine is the key step and has been achieved through the use of a Suzuki coupling. Since the coupling reaction is conducted under aqueous conditions, it is unnecessary to protect and then deprotect the hydroxyl groups, thus saving several steps and improving overall yield...