Characterization and representative structures of N-oligosaccharides bound to apolipoprotein H

Abstract

We studied the structure of N-linked carbohydrates bound to apolipoprotein H by a combination of two methods which make use of lectins. Digoxigenin-labelled lectins are used for the structural characterization of carbohydrate chains of glycoproteins. Concanavalin A lectin affinity chromatography was used to analyse apolipoprotein H according to the characteristics of its carbohydrate chain inner to sialic acid residues. Our results from digoxigenin-labelled lectins analysis showed that apolipoprotein H gave positive bands to SNA, DSA, GNA, PNA and AAA lectins. Apolipoprotein H gave a negative band when reacted with MAA lectin. When we applied apolipoprotein H onto the Concanavalin A lectin column no detectable amounts of protein were eluted with Concanavalin A buffer. After adding a buffer with low sugar concentration (10 mM glucoside) a large amount of apolipoprotein H was recovered. These molecules of apolipoprotein H weakly bound to the lectin. When a higher sugar concentration (500 mM mannoside) was added most of the sample applied was eluted. These molecules of apolipoprotein H firmly bound to the column having high affinity for the lectin. These results combined with those coming from the Abbre6iations: apo H, apolipoprotein H; SDS -PAGE, sodium dodecyl sulfate polyacrylamide gel

Apolipoprotein H, an Acute Phase Protein, a Performing Tool for Ultra-Sensitive Detection and Isolation of Microorganisms from Different Origins

“…5) (Gambino et al, 1997): Complex, hybrid and Mannose-rich. These structures have a common motif consisting in two N-acetylglucosamins and three mannoses, differing in the antennas composition, and their number varies from two to five.…”