Single step syntheses of lactosylated clusters by telomerizations

Combining glycocluster synthesis with protein engineering: an approach to probe into the significance of linker length in a tandem-repeat-type lectin (galectin-4)

Complementarity in lectin-glycan interactions in situ is assumed to involve spatial features in both the lectin and the glycan, giving a functional meaning to structural aspects of the lectin beyond its carbohydrate-binding site. In combining protein engineering with glycocluster synthesis, it is shown that the natural linker length of a tandem-repeat-type human lectin (galectin-4) determines binding properties in two binding assays (using surface-presented glycoprotein and cell surface assays). The types of glycocluster tested included bivalent lactosides based on tertiary amides of terephthalic, isophthalic, 2,6-naphthalic and oxalic acids as well as bivalent H(type 2) trisaccharides grafted on secondary/tertiary terephthalamides and two triazole-linker-containing cores. The presented data reveal a marked change in susceptibility to the test compounds when turning the tandem-repeat-type to a proto-type-like display. The testing of glycoclusters is suggested as a general strategy to help to delineate the significance of distinct structural features of lectins beyond their contact sites to the glycan.

Facile synthesis of 1-thio-beta-lactoside clusters scaffolded onto p-methoxyphenyl, beta-D-galactopyranoside, beta-D-glucopyranoside, and lactoside

The free-radical addition of 2,3,4,6-tetra-O-acetyl-beta-D-galactopyranosyl-(1-->4)-2,3,6-tri-O-acetyl-1-thio-beta-D-glucopyranose to the allyl ether functions of p-methoxyphenyl per-O-allyl-D-galactopyranoside, D-glucopyranoside, and lactoside provides a concise and effective route for synthesis of glycoside clusters, of use for exploring anti-metastatic activity.

Peptide and glycopeptide dendrimers. Part II

Recent progress in peptide and glycopeptide chemistry make the preparation of peptide and glycopeptide dendrimers of acceptable purity, with designed structural and immunochemical properties reliable. New methodologies using unprotected peptide building blocks have been developed to further increase the possibilities of their design and improve their preparation and separation. The sophisticated design of peptide and glycopeptide dendrimers has led to their use as antigens and immunogens, for serodiagnosis and other biochemical uses including drug delivery. Dendrimers bearing peptide with predetermined secondary structures are useful tools in protein de novo design. This article covers synthesis and applications of multiple antigen peptides (MAPs), multiple antigen glycopeptides (MAGs), multiple antigen peptides based on sequential oligopeptide carriers (MAP-SOCs), glycodendrimers and template-assembled synthetic proteins (TASPs). In part II the preparation of MAPs, and the utility of glycodendrimers and TASPs are discussed.

Syntheses and some applications of chemically defined multivalent glycoconjugates

Classical multivalent neoglycoproteins have been widely used to study a great number of carbohydrate-protein interactions. The synthesis of other neoglycoconjugates with various shapes, valencies, and conformations has reached considerable levels of sophistication and holds promise as a new tool for glycobiology and biomedical applications. Within the last few years, advances have been made towards both the syntheses and understanding of the antigenic properties of water-soluble glycopolymers. Some of these glycopolymers are finding applications as inhibitors of microbial adhesins and as carriers for drug delivery to specific cells. Novel dendritic carbohydrate structures are emerging as potent ligands for carbohydrate-binding proteins.