ISOLATION AND CHARACTERIZATION BY ELECTROSPRAY-IONIZATION MASS-SPECTROMETRY AND HIGH-PERFORMANCE ANION-EXCHANGE CHROMATOGRAPHY OF OLIGOSACCHARIDES DERIVED FROM HYALURONIC-ACID BY HYALURONATE LYASE DIGESTION - OBSERVATION OF SOME HERETOFORE UNOBSERVED OLIGOSACCHARIDES THAT CONTAIN AN ODD NUMBER OF UNITS

Hyaluronic acid was degraded with hyaluronate lyase (E.C. 4.2.2.1, fro m Streptomyces hyalurolyticus), and the resulting oligosaccharides up to dp 16 were characterized by electrospray-ionization mass spectromet ry (ESIMS) and high-performance anion-exchange chromatography (HPAEC) with pulsed amperometric detection (PAD). In accordance with the known regiospecificity of the enzyme, the products included even-numbered o ligosaccharides of structure beta-D-4en-thrHexpA-(1 --> 3)-[beta-D-Glc pNAc-(1 --> 4)-beta-D-GlcpA](n)-(1 --> 3)-D-GlcpNAc. Minor amounts of novel and unexpected odd-numbered oligomers, having the structure beta -D-4en-thrHexpA-(1 --> 3)-[beta-D-GlcpNAc-(1 --> 4)-D-GlcpA](n), were also isolated and characterized. This study, in addition to others beg inning to appear in the literature, demonstrates the usefulness of ESI MS and HPAEC-PAD in the analysis and characterization of anionic glyco saminoglycan-type oligosaccharides. (C) 1997 Elsevier Science Ltd.