Glycosylation basic mechanisms

Expected J values (Hz) for the Basic Conformations Around Angles for /3- and a-Linked C-Glycosyl Compounds, Deduced by Applying the Generalized Karplus Equation Proposed by Altona to the Geometries Provided by MM3 Molecular-mechanics Calculations ... 

Slow proton transfer makes possible the occurrence of iso mechanisms -mechanisms in which the form of the enzyme released after catalysis is different to that at the start of the cycle. A candidate would be any inverting glycosidase, which is released with the acid group deprotonated and the basic group protonated [Figure 1(b)], although no example in the glycosyl transfer area has yet been demonstrated (the best example is proline racemase, " in which two cysteines act, one as an acid and the other as a base). 

At the current time, a wealth of knowledge for protein glycosylation has been obtained from numerous studies conducted in eukaryotes rather than in bacteria. However, the simplicity of the bacterial systems has made them a great model for studying different basic aspects entailed in protein glycosylation. Moreover, recent studies identified some unique protein glycosylation mechanisms in bacteria such as Neisseria and Pseudomonas that have not been described for any other eukaryotes before. 

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