Glycosidic high-energy

NAD+ possesses some non-redox functions as well. The glycosidic linkage between nicotinamide and ribose is a high-energy bond. The energy provided by... 

Those nucleosides found in the nucleic acids DNA and RNA involve the joining of ribose of deoxyribose to a purine or a pyrimidine base. One such nucleoside is adenosine, in which a nitrogen of adenine is linked to carbon 1 of the pentose, ribose. In this form it is a component of RNA but as a phosphory-lated derivative of adenosine (e.g. ATP), which is a high energy compound, it fulfils an important role in metabolism. The dinucleotides NAD and NADP are two cofactors necessary for many enzymic transformations and these also contain /V-glycosides of ribose phosphate. Other important nucleosides are found... 

Collision-induced dissociation FAB MS/MS trace of the (M + Na)+ of an oligosaccharide, measured at high energy. It allows one to determine the positional isomers of all its glycosidic bonds. Reproduced (modified) from Lemoine J., Fournet B., Despeyroux D., Jennings R., Rosenberg R. and de Hoffmann E., J., Am.Soc. Mass Spectrom., 4, 197, 1993, with permission. 

The two amidotransferases in the purine biosynthetic pathway differ in that one requires ATP while the other does not. It would appear that the pyrophosphate-glycoside bond of PP-ribose-P is of the high-energy type, and that PP-ribose-P serves both as substrate and energy source... 

Both zanamivir and oseltamivir are structurally similar to Al-acetyl neuraminic acid (NeuSAc), mimicking the high-energy ojycarbenium intermediate 20, generated during the enzymatic cleavage of the a-glycosidic bond of NeuSAc. 

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