RECOGNITION OF N-ACETYLGLUCOSAMINE (GLyNAc) AND POLY-N-ACETYLLACTOSAMINE RESIDUES IN VESSELS OF THE RAT PINEAL GLAND

Abstract

Lectins are proteins with binding sites that recognize a specific sequence of sugar moieties in complex glycoconjugates. In the present study the tomato lectin-Lycopersicon esculentum (LEL) (a selective microglial and endothelial marker) has been reported to recognize specific residues of N-acetylglucosamine (GlyNAc) and poly-N-acetyllactosamine. In the pineal gland the biotinylated LEL was used to investigate the appearance of these sugar residues in the structures of the rats during their development and adult life. Our results showed that the binding of LEL occurred exclusively in the material adherents on surface of the endothelia of the vessels in the peripheral and central regions of the gland. An exception can be cited to rats in first postnatal day where the vessels in the central region did not display the LEL-reaction. In all animals studied and, from 3-postnatal day onwards the LEL-reactions could be observed within the central space of pseudo-rosettes also characterizing this space as a vessel.

Receptor-destroying enzyme (RDE) from Vibrio cholerae modulates IgE activity and reduces the initiation of anaphylaxis

“…We also detected a much smallersized band of RDE (II)-treated IgE, around 150 kDa (Fig. 2A, lanes [13][14][15][16]. Moreover, we obtained the same results by CBB staining (Fig.…”

“…S4, lanes 3-9), similar to the situation with IgG (Fig. S4, lanes [12][13][14][15][16][17][18]. These results suggest that sialidase is not primarily responsible for the modification of IgE by RDE (II).…”

“…6). LEL recognizes N-GlcNAc ␤-1,4-linked N-GlcNAc oligomers up to four carbohydrate units ((GlcNAc) 2-4 ) or Gal␤1-4GlcNAc␤1-3 oligomers ((LacNAc) n ) (15)(16)(17)(18). PHA-L binds to tetra-antennary complex oligosaccharides (Gal(␤1-4)GlcNAc(␤1-6)Man).…”

“…In this study, we showed that RDE (II) altered the structure of IgE and abrogated IgE binding to Fc⑀RI on mast cells, which is directly related to the mast cell degranulation, thereby preventing anaphylaxis. Furthermore, we identified that RDE (II)-treated IgE had reduced capacity of binding to Lycopersicon esculentum (LEL), which recognizes poly N-acetylglucosamine (GlcNAc) and poly-N-acetyllactosamine (LacNAc) (15)(16)(17)(18), by lectin microarray analysis using 96 lectins (19,20). Taken together, RDE (II) was found to have the specific characteristics necessary to modulate the glycan on IgE, when compared with IgG.…”