Glycopeptides structural features

Jolles, J., Schoentgen, F Alais, C., Fiat, A.-M. and Joll6s, P 1972A. Studies on the primary structure of cow K-casein. Structural features of para-K-casein N-terminal sequence of K-casein-glycopeptides studied with a sequencer. Helv. Chim. Acta 55, 2872-2883. 

The first known structure within the glycopeptide family of antibiotics was vancomycin. Vancomycin, the clinically most important glycopeptide was discovered in 1956 however, its structure was disclosed only 25 years later, after correcting404,405 the previous X-ray structure of CDP-1406 by NMR.407 Since that time hundreds of related glycopeptides were discovered or prepared as semisynthetic compounds. More than 12 000 papers were published about the vancomycin topic within the last 20 years. Some recent reviews40 1 give in-depth accounts of the topic. Here we just summarize some basic structural features of the main representatives (vancomycin, eremomycin, teicoplanin, ristocetin-A) in Scheme 6. 

The sialic acids are a family of ubiquitous aminosugars found in some bacteria and invertebrates, and in all vertebrate tissues. They are normally found as nonreducing termini of complex heteropolymers such as glycoproteins, glycopeptide hormones, and glycolipids. The chemistry and structural features of these compounds are described in Chapter 1 of this volume. 

One of the most characteristic features of FRET is its sensitive dependency on the fluorophore distance. This is advantageously used to evaluate structures and conformational changes of peptides, glycopeptides, and proteins among other molecules [164-166], The conformational change of the lipopeptide antibiotic daptomycin from an inactive linear form to a biological active cyclic form... 

The surface glycoprotein of Halobacterium salinarium was the first glycosylated protein detected in prokaryotes [109]. More recent work on the chemical structure of glycopeptides [110-113] and the primary structure of the polypeptide moiety of the surface glycoprotein of Halobacterium halobium - an organism related to Hb. salinarium at the species level - has led to a detailed picture (Fig. 15A) of this molecule. Its main features are ... 

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