X-ray analysis studies1' 2 on the relative modes of association of various inhibitors and substrates with lysozyme have led to a proposal for the catalytic mechanism of the enzyme.3'4 This proposal suggests that the enzyme catalyzes the formation of a carbonium ion at C1 of the glycosidic bond undergoing hydrolysis and, further, provides it with steric and electrostatic stabilization. To date, ...

0008-6215/$ see front matter 2010 Elsevier Ltd. A doi:10.1016/j.carres.2010.03.017 * Corresponding authors. Tel.: +1 504 280 6856; fa tel.: +1 504 286 4410; fax: +1 504 286 4217 (A.D.F.). E-mail addresses: [email protected] (E.D. Stevens), French). a,a-Trehalose is of interest because of its cryoprotective and antidessicant properties, and because it possesses various technical anomalies such as...

BACKGROUND Degradation of cellulose to glucose requires the cooperative action of three classes of enzymes, collectively known as cellulases. Endoglucanases randomly bind to cellulose surfaces and generate new chain ends by hydrolyzing β-1,4-D-glycosidic bonds. Exoglucanases bind to free chain ends and hydrolyze glycosidic bonds in a processive manner releasing cellobiose units. Then, β-glucosi...

The Cori ester α-d-glucose 1-phosphate (αGlc 1-P) is a high-energy intermediate of cellular carbohydrate metabolism. Its glycosidic phosphomonoester moiety primes αGlc 1-P for flexible exploitation in glucosyl and phosphoryl transfer reactions. Two structurally and mechanistically distinct sugar-phosphate phosphatases from Escherichia coli were characterized in this study for utilization of αGl...

Three kinds of polysaccharides, namely, BSP1A, BSP2A, and BSP3B, were isolated from raw bamboo shoot (Dendrocalamus latiflorus) after purification and classification by DEAE cellulose-52 (ion-exchange chromatography) and Sephadex G-50. The molecular weights of BSP1A, BSP2A, and BSP3B were 10.2, 17.0 and 20.0 kDa, respectively, which were measured through GPC (gel performance chromatography) met...

Sea cucumbers produce numerous compounds with a wide range of chemical structural diversity. Among these, saponins are the most diverse and include sulfated, non-sulfated, acetylated and methylated congeners with different aglycone and sugar moieties. In this study, MALDI and ESI tandem mass spectrometry, in the positive ion mode, were used to elucidate the structure of new saponins extracted f...

Guanine rich sequences adopt a variety of four stranded structures, which differ in strand orientation and conformation about the glycosidic bond even though they are all stabilised by Hoogsteen hydrogen bonded guanine tetrads. Detailed model building and molecular mechanics calculations have been carried out to investigate various possible conformations of guanines along a strand and different...

Natural abundance carbon 13 nuclear magnetic resonance spectroscopy was used to confirm and extend the structural properties of peptidophosphogalactomannan (pPGM) from Penicillium charlesii. The major resonances for phosphogalactomannan (PGM) and phosphomannan (PM) were assigned. Based on comparison of chemical shifts of carbon 13 resonance signals in phosphogalactomannan with those of galactoc...