Chemical synthesis of 6(GlcNAc)- and 6(Gal)-O-sulfated SiaLe(X) tetrasaccharides in spacer-armed form.

Practical synthesis of tetrasaccharide sulfates, 6((GlcNAc))-O-Su-SiaLe(X)-OCH(2)CH(2)CH(2)NH(2) and 6((Gal))-O-Su-SiaLe(X)-OCH(2)CH(2)CH(2)NH(2) (Su( )SO(3)H), selectin ligands, and leu- kocyte trafficking agents is presented. Both sulfates were synthesized starting from the same precursor, protected SiaLe(x), by the conventional procedures of carbohydrate chemistry. The sulfated SiaLe(x) derivative was modified at the spacer group to give 6((Gal))-O-Su-SiaLe(x)- OCH(2)CH(2)CH(2)NH-COCH(2)CH(2)C[triple bond]CH, convenient for "click chemistry" mode conjugation with an azido carrier, particularly, for the synthesis of an immunogen.

[Sialylation of N-carbohydrate chains of glycoproteins with immobilized trans-sialidase from Trypanosoma cruzi].

Alpha2,3-sialylation of the lactosamine type N-glycans with trans-sialidase from Trypanosoma cruzi is reported. Trans-sialidase (160 kDa, pI 5.35-5.

N-Terminal segment of potato virus X coat protein subunits is glycosylated and mediates formation of a bound water shell on the virion surface.

The primary structures of N-terminal 19-mer peptides, released by limited trypsin treatment of coat protein (CP) subunits in intact virions of three potato virus X (PVX) isolates, were analyzed. Two wild-type PVX strains, Russian (Ru) and British (UK3), were used and also the ST mutant of UK3 in which all 12 serine and threonine residues in the CP N-terminal segment were replaced by glycine or alanine. With the help of direct carbohydrate analysis and MS, it was found that the acetylated N-terminal peptides of both wild-type strains are glycosylated by a single monosaccharide residue (galactose or fucose) at NAcSer in the first position of the CP sequence, whereas the acetylated N-terminal segment of the ST mutant CP is unglycosylated.

New feature of angiotensin-converting enzyme: carbohydrate-recognizing domain.

Self carbohydrate-mediated dimerization of glycoprotein angiotensin-converting enzyme (ACE) was demonstrated. The dimerization was studied in the reverse micelle experimental system as a model of biomembrane situation. Asialo-ACE or agalacto-ACE was able to form a dimer, whereas deglycosylated ACE and sequentially desialylated and degalactosylated ACE failed to dimerize.