Sugar phosphorylases

Almost simultaneously with the work on sugar phosphorylase, two separate groups developed the two-step mechanism for hydrolyses catalysed by peptidases and esterases. Their mechanism, which is the one that we accept today, postulated an acylated enzyme as intermediate. I. B. Wilson,... 

E3 UDP-sugar phosphorylase. E4 pyrophosphatase. (Below) Synthesis of 6 -deoxy-6 -fluorosucrose. El, sucrose synthetase E2, pyruvate kinase E3, UDP-glucose pyrophosphorylase E4, pyrophosphatase. All enzymes (150 U each) are co-immobilized in polyacrylamide gel. The reactions are carried out in triethanolamine buffer (50 mM) containing MgCl2 (10 mM) with pH being controlled at 7.5 by addition of IN NaOH. The 500-mL reaction mixture contains glucose-... 

Sugar phosphorylases are another choice to synthesise glycosyl linkages. These enzymes catalyse the reversible phosphorolysis of their particular substrates to form monosaccharide 1-phosphates, and their reverse reaction has often been utilised in... 

Several simple deoxyfluoro sugars and glycosyl fluorides were utilized " as probes for hydrogen bonding in the glycogen phosphorylase-o-glucose complex. 

Khan MTH (2007) Recent Advances on the Sugar-Derived Heterocycles and Their Precursors as Inhibitors Against Glycogen Phosphorylases (GP). 9 33-52 Khan MTH (2007) Heterocyclic Compounds Against the Enzyme Tyrosinase Essential for Melanin Production Biochemical Features of Inhibition. 9 119-138 Khan MTH (2007) Molecular Modeling of the Biologically Active Alkaloids. 10 75-98 Khan MTH, Ather A (2007) Microbial Transformation of Nitrogenous Compoimds. 10 99-122... 

Sugar-derived Heterocycles and Their Precursors as Inhibitors Against Glycogen Phosphorylases (GP)... 

Cyprinus carpio 0.5 after 6 days, 300% increase in phosphorylase and 200% increase in glucose-6-phosphatase activities in liver increase in sugar level and serum lactic dehydrogenase activity 18... 

His first work in the Laboratory of Biological Chemistry was on the purification and properties of potato phosphorylase, but he soon changed his subject to the study of amino-containing sugars. It was not well understood at that time whether there were impurities in the products of separation and purification of proteins. Consequently, Onodera made up his mind to devote his whole life to identifying the chemical nature of amino-containing sugars. 

The function of the sulfate residue in these polysaccharides is unknown but the suggestion has been made that just as starch is synthesised from D-glucose 1-phosphate by the action of phosphorylase, so the seaweed polysaccharides are formed from the appropriate sugar sulfate by reaction with a sulfatase. ... 

Phosphorylases remove the ribose sugars to yield the bases guanine or hypoxan-thine (from adenine or inosine nucleosides). 

Fig. 9a and b. Difference Fourier maps calculated from Laue diffraction data showing maltoheptose bound in phosphorylase b. The Laue map shown in a is calculated with a subset of 9029 unique data at 2.5 A resolution. A positive contour at half maximal peak height is shown, b is an enlargement of a and shows 4 of the 7 sugar units, the 3 central units have the highest occupancies. Side chain movements produce the two extra lobes of density. (Figures courtesy of J. Hajdu)... 

Pfannemtiller et al. showed that it is possible to obtain carbohydrate-containing amphiphiles with various alkyl chains via amide bond formation. For this, mal-tooligosaccharides were oxidized to the corresponding aldonic acid lactones, which could subsequently be coupled to alkylamines [128-136]. Such sugar-based surfactants are important industrial products with applications in cosmetics, medical applications etc. [137-139]. The authors were also able to extend the attached mal-tooligosaccharides by enzymatic polymerization using potato phosphorylase, which resulted in products with very interesting solution properties [140, 141]. 

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