Oligosaccharides high mannose

The use of f.a.b.-m.s. to monitor hydrolysis and acetolysis reactions is illustrated by studies on a yeast high-mannose oligosaccharide containing two phosphoric esters (19). The molecular-ion region of the negative f.a.b. 

The compositions of high-mannose oligosaccharides isolated from urine of animals suffering from genetic or chemically induced mannosidoses have been assigned from their f.a.b.-mass spectra. After chromatography, some samples were sufficiently pure to be examined underivatized. Others required conversion into their peracetylated derivatives. 

N-Linked oligosaccharides, Degree of polymerization of neutral oligosaccharides, Degree of methylation and acetylation of pectin, High mannose oligosaccharides ... 

Figure 17-5. Synthesis of the mannose 6-phosphate recognition marker. R represents the high-mannose oligosaccharide of newly synthesized lysosomal enzymes. Reaction 1 is catalyzed by UDP-A,-acetylglucosamine lysosomal enzyme Ar-acetylglucosaminyl-1 -phosphotransferase. Reaction 2 is catalyzed by iV-acetylglucosamine-l-phosphodiester-iV-ace tylgluco saminidase.

In vivo, the CH3 group in the reaction scheme is representative of the rest of the high-mannose oligosaccharide intermediate. 

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