T1 - Synthesis of 5-deoxy-5-phosphinyl-D-galactopyranose derivatives
Galactose and lactose, which is composed of glucose and galactose, can promote dental caries .
Two of these methods used D-galactose as the starting material.
Sardzik, Robert; Green, Anthony P.; Laurent, Nicolas; Both, Peter; Fontana, Carolina; Voglmeir, Josef; Weissenborn, Martin J.; Haddoub, Rose; Grassi, Paola; Haslam, Stuart M.; Widmalm, Goran; Flitsch, Sabine L. Chemoenzymatic Synthesis of O-Mannosylpeptides in Solution and on Solid Phase. JOURNAL OF THE AMERICAN CHEMICAL SOCIETY. 134(10); 4521 – 4524. – MAR 14 2012
The gal operon of bacteria encodes enzymes of galactose metabolism that constitute an amphibolic pathway and is transcribed by two promoters. Several cis-acting DNA sequences (control elements) and a variety of regulatory proteins, including a histone-like protein, modulate the two promoters in a multitude of ways usually found in animals and not in bacteria (Table 1). The gal operon has revealed several new features of gene-specific transcriptional regulation that were previously unrecognized. Perhaps such multivalent control mechanisms are required to regulate the synthesis of amphibolic enzymes.
The ratio of mannose to galactose is 2:1.
Galactose is absorbed in the small intestine by the same mechanism as glucose, that is by the help of SGLT-1 and GLUT-2 transport proteins in the small intestinal lining .
In the rare genetic disorder glucose-galactose malabsorption, the absorption of galactose and glucose is reduced .
RNA-directed cell-free synthesis of the galactose …
The structural genes and the associated regulatory elements of the gal operon are shown in Figure 2. The gal operon is transcribed from two promoters, P1 and P2, which are separated by 5 base pairs (bp) (4, 5). The dominant regulator of the gal operon is the Gal repressor (GalR) (6). GalR, together with the histone-like protein, HU, acting as a corepressor, keeps the expression from the gal promoters low (7, 8). The operon is induced 15-fold in the presence of D-galactose or some of its nonmetabolizable analogs, such as D-fucose (9). The inducer lifts the repression by an allosteric effect on GalR. It is not known whether the true inducer is the a- or the b-anomer of the sugar, or both. Besides the major negative control by GalR and HU, the two promoters are also regulated by GalR alone (10), by a Gal isorepressor, GalS (11-13), and by a complex of cyclic AMP (cAMP) bound to cyclic AMP receptor protein (CRP), cAMP*CRP (4, 5, 14-16). As described below, P1 and P2 are regulated by these regulators in opposite directions. The gal promoters are also modulated by cis-acting DNA sequences without the participation of any regulatory proteins.
Transcription of the gal operon from the P2 promoter is very low when the concentration of UTP is high and vice versa, both in vivo and in vitro (19). UTP regulates the step of promoter clearance by RNA polymerase at the P2 promoter in an intriguing way. In vitro, RNA polymerase clears at P2 poorly and makes a large amount of aborted RNA oligomers, unlike at P1. At high concentrations of UTP, it also synthesizes pseudo-templated RNA oligomers of the composition
Galactose Metabolism - The Medical Biochemistry Page
a-L-Galactose-1-phosphate dipotassium salt | 262856 …
The mannopyranose units are linked with 1β4 linkages to whichgalactopyranose units are attached with 1α6 linkages.
PLOS ONE: Manipulation of the Rice L-Galactose …
Galactomannans are present in several vegetable gums that are used to increase the viscosity of food products.
A novel synthesis of l -fucose from d -galactose - …
Galactose - Wikipedia
pathway required for L-galactose synthesis in K
The purpose of this communication is to report an easy and inexpensive route for the synthesis of L-fucose from D-galactose in good yield using inexpensive reagents and involving mostly crystalline intermediates.
CAS No.2438-80-4,L-Galactose, 6-deoxy- …
Rannes, Julie B.; Ioannou, Avgousta; Willies, Simon C.; Grogan, Gideon; Behrens, Carsten; Flitsch, Sabine L.; Turner, Nicholas J. Glycoprotein Labeling Using Engineered Variants of Galactose Oxidase Obtained by Directed Evolution. JOURNAL OF THE AMERICAN CHEMICAL SOCIETY. 133(22); 8436 – 8439. – JUN 8 2011
O-linked glycoproteins: The synthesis of O-linked ..
Noble, Gavin T.; Craven, Faye L.; Voglmeir, Josef; Sardzik, Robert; Flitsch, Sabine L.; Webb, Simon J. Accelerated Enzymatic Galactosylation of N-Acetylglucosaminolipids in Lipid Microdomains. JOURNAL OF THE AMERICAN CHEMICAL SOCIETY. 134(31); 13010 – 13017. – AUG 8 2012
a disaccharide composed of D-galactose and 3,6-anhydro-L ..
In the course of synthesis of some biologically active oligosaccharides, it was therefore deemed pertinent to develop an easy route for the synthesis of L-fucose from a readily available source.
Galactose is phosphorylated by galactokinase to galactose-l -P ..
Through the use of modern molecular biology techniques, it is possible to transfer individual enzymes from their host organism and produce them in more amenable laboratory strain bacteria. This allows them to be more easily studied, engineered and integrated into new enzyme cascades, both in whole cell systems and as cell-free formulations. In the Flitsch group we are interested in the tailoring of various enzymes to perform specific, synthetically-useful reactions and incorporating these into bespoke pathways for the production of industrially- and biomedically-relevant compounds. Examples of target products of particular interest include high value chiral amines as pharmaceutical / fine chemical precursors and glycoconjugates as chemical biology probes for glycobiotechnology.
form the UDP-galactose used in lactose synthesis; ..
Das, Nirmolendu Roy Department of Biological Chemistry, Indian Association for the Cultivation of Science, Calcutta 700 032, India Received 13 October 1994;accepted2 December1994 Keywords." Synthesis; L-Fucose;D-Galactose L-Fucose is ubiquitous in nature and its presence in glycoconjugates and other biologically important moieties plays an important role in the activity of these substances .
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