28619-26-3Relevant academic research and scientific papers
Multiplex detection of enzymatic activity with responsive lanthanide-based luminescent probes
Pershagen, Elias,Borbas, K. Eszter
supporting information, p. 1787 - 1790 (2015/02/19)
Multiplex analyte detection in complex dynamic systems is desirable for the investigation of cellular communication networks as well as in medical diagnostics. A family of lanthanide-based responsive luminescent probes for multiplex detection is reported. The high modularity of the probe design enabled the rapid assembly of both green and red emitters for a large variety of analytes by the simple exchange of the lanthanide or an analyte-cleavable caging group, respectively. The real-time three-color detection of up to three analytes was demonstrated, thus setting the stage for the non-invasive investigation of interconnected biological processes. © 2015 Wiley-VCH Verlag GmbH & Co. KGaA , Weinheim.
Mechanistic evaluation of MelA α-galactosidase from citrobacter freundii: A family 4 glycosyl hydrolase in which oxidation is rate-limiting
Chakladar, Saswati,Cheng, Lydia,Choi, Mary,Liu, James,Bennet, Andrew J.
experimental part, p. 4298 - 4308 (2012/03/22)
The MelA gene from Citrobacter freundii, which encodes a glycosyl hydrolase family 4 (GH4) α-galactosidase, has been cloned and expressed in Escherichia coli. The recombinant enzyme catalyzes the hydrolysis of phenyl α-galactosides via a redox elimination-addition mechanism involving oxidation of the hydroxyl group at C-3 and elimination of phenol across the C-1-C-2 bond to give an enzyme-bound glycal intermediate. For optimal activity, the MelA enzyme requires two cofactors, NAD+ and Mn2+, and the addition of a reducing agent, such as mercaptoethanol. To delineate the mechanism of action for this GH4 enzyme, we measured leaving group effects, and the derived βlg values on V and V/K are indistinguishable from zero (-0.01 ± 0.02 and 0.02 ± 0.04, respectively). Deuterium kinetic isotope effects (KIEs) were measured for the weakly activated substrate phenyl α-d-galactopyranoside in which isotopic substitution was incorporated at C-1, C-2, or C-3. KIEs of 1.06 ± 0.07, 0.91 ± 0.04, and 1.02 ± 0.06 were measured on V for the 1-2H, 2- 2H, and 3-2H isotopic substrates, respectively. The corresponding values on V/K were 1.13 ± 0.07, 1.74 ± 0.06, and 1.74 ± 0.05, respectively. To determine if the KIEs report on a single step or on a virtual transition state, we measured KIEs using doubly deuterated substrates. The measured DV/K KIEs for MelA-catalyzed hydrolysis of phenyl α-d-galactopyranoside on the dideuterated substrates, DV/K(3-D)/(2-D,3-D) and DV/K (2-D)/(2-D,3-D), are 1.71 ± 0.12 and 1.71 ± 0.13, respectively. In addition, the corresponding values on V, DV (3-D)/(2-D,3-D) and DV(2-D)/(2-D,3-D), are 0.91 ± 0.06 and 1.01 ± 0.06, respectively. These observations are consistent with oxidation at C-3, which occurs via the transfer of a hydride to the on-board NAD+, being concerted with proton removal at C-2 and the fact that this step is the first irreversible step for the MelA α-galactosidase-catalyzed reactions of aryl substrates. In addition, the rate-limiting step for Vmax must come after this irreversible step in the reaction mechanism.
Cysteine-based mannoside glycoclusters: Synthetic routes and antiadhesive properties
Schierholt, Alexander,Hartmann, Mirja,Schwekendiek, Kirsten,Lindhorst, Thisbe K.
experimental part, p. 3120 - 3128 (2010/08/19)
Clustermannosides of different valency were synthesised based on cysteine. By employing the orthogonally protected amino acid as scaffold molecule, a variety of structurally varied products can be obtained according to different synthetic routes. Testing of the prepared glycoclusters as inhibitors of type 1 fimbriae mediated bacterial adhesion is reported, giving hints about the influence of sugar valency, sugar scaffolding, and the nature of the glycosidic aglycon in this testing system.
Gold catalysis in glycosylation reactions
G?tze, Sebastian,Fitzner, Roland,Kunz, Horst
scheme or table, p. 3346 - 3348 (2010/03/04)
Glycosylation of alcohols containing acid-sensitive groups, as for example 1,2-5,6-di-O-isopropylidene-glucofuranose, Fmoc-threonine tert-butyl ester or farnesol, is achieved using gly-cosyl trichloroacetimidates activated by gold(I) chloride (5-10 mol%). While glycosylation with 2-O-acyl protected glycosyl donors proceeds with 1,2-trans-selectivity, non-neighboring group active glycosyldonors give mixtures of anomeric glycosides or -glycosides depending upon their structure and the reactivity of the glycosyl acceptor. Georg Thieme Verlag Stuttgart New York.
Glycosylated prodrugs, their method of preparation and their uses
-
, (2008/06/13)
Glycosylated prodrugs, a preparation method therefor, and their use with tumor-specific immunoenzymatic conjugates for the treatment of cancer, are described. These anthracycline prodrugs have formula (I). STR1
Stannic chloride promoted synthesis of mannosides
Irani, Rustom K,Sinha, Bharati,Bose, J L
, p. 519 - 521 (2007/10/02)
Use of anhyd.SnCl4 has been described for the synthesis of aryl, arylalkyl and alkyl α-D-mannopyranosides.A possible mechanism for the formation of α-anomer in these reactions is discussed.
