Electrospray ionization Fourier transform mass spectrometric analysis of intact bikunin glycosaminoglycan from normal human plasma

A mixture of glycosaminoglycan (GAG) chains from a plasma proteoglycan bikunin was fractionated using native, continuous-elution polyacrylamide gel electrophoresis, and the resulting fractions were analyzed by electrospray ionization Fourier transform mass spectrometry (ESI FTMS). Molecular mass analysis of the intact GAG afforded information about the length and composition of GAG chains in the mixture. Ambiguity in the interpretation of the intact GAG mass spectra was eliminated by conducting an additional experiment in which the GAG chains of known molecular mass were treated with a GAG-degrading enzyme, chondroitinase ABC, and the digestion products were analyzed by ESI FTMS. The plasma bikunin GAG chains consisted predominantly of odd number of saccharides, although few chains consisting of even number of saccharides were also detected. Majority of the analyzed chains were tetrasulfated or pentasulfated and comprised by 29–41 monosaccharides.

The length and number of sulfo groups of intact glycosaminoglycan chains of a plasma proteoglycan bikunin are determined by ESI FTMS.Figure optionsDownload high-quality image (116 K)Download as PowerPoint slideResearch highlights▶ Continuous-elution polyacrylamide gel electrophoresis to purify bikunin proteoglycan. ▶ Electrospray ionization Fourier transform mass spectrometry for intact bikunin glcosaminoglycan chains. ▶ Plasma bikunin GAG chains consisted predominantly of odd number of saccharides.