HIGH-PERFORMANCE CAPILLARY ELECTROPHORETIC CHARACTERIZATION OF DIFFERENT TYPES OF OLIGO- AND POLYSIALIC ACID CHAINS

Abstract We have carried out comparative structural analysis of novel oligo- and polysialic acid chains from diverse sources. Controlled acid hydrolysates of (a) colominic acid, α2→8-linked homopolymer of N -acetylneuraminic acid (Neu5Ac), (b) α2→8-linked oligo/polyNeu5Gc chains present in rainbow trout egg polysialoglycoprotein, and (c) α2→8-linked oligomers of deaminoneuraminic acid (KDN) residues of KDN-rich glycoprotein derived from rainbow trout vitelline envelope were analyzed by high-performance capillary electrophoresis (HPCE). The results showed that three different types of α2→8-linked oligosialic acids having same degree of polymerization can be separated by HPCE. A partial hydrolysate of colominic acid with mild acid was shown by CE to form intramolecular esters during the controlled hydrolysis and the subsequent workup procedure. In contrast, lactonization of (→5- O glycolyl -Neu5Gcα2→) n , α2→5- O glycolyl -linked homopolymer of N -glycolylneuraminic acid (Neu5Gc) present in the egg jelly coat of sea urchin, did not take place as readily as in (→8Neu5Acα2→) n .