Glycobiology Advance Access originally published online on September 15, 2006
Glycobiology 2007 17(1):25-35; doi:10.1093/glycob/cwl046
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Optimized extraction of glycosaminoglycans from normal and osteoarthritic cartilage for glycomics profiling
2 Department of Biochemistry, Boston University School of Medicine, MS Resource, 670 Albany Street, Boston, MA 02118, USA
3 Department of Orthopedic Surgery, Brigham and Women's Hospital and Harvard Medical School, Boston, MA 02115
1 To whom correspondence should be addressed; Tel: +1 617-638-6762; Fax: +1 617-638-6760; e-mail: jzaia{at}bu.edu
Received on June 14, 2006; revised on August 11, 2006; accepted on September 5, 2006
Articular cartilage is a highly specialized smooth connective tissue whose proper functioning depends on the maintenance of an extracellular matrix consisting of an integrated assembly of collagens, glycoproteins, proteoglycans (PG), and glycosaminoglycans. Isomeric chondroitin sulfate glycoforms differing in position and degree of sulfation and uronic acid epimerization play specific and distinct functional roles during development and disease onset. This work introduces a novel glycosaminoglycan extraction method for the quantification of mixtures of chondroitin sulfate oligosaccharides from intact cartilage tissue for mass spectral analysis. Glycosaminoglycans were extracted from intact cartilage samples using a combination of ethanol precipitation and enzymatic release followed by reversed-phase and strong anion exchange solid-phase extraction steps. Extracted chondroitin sulfate glycosaminoglycans were partially depolymerized using chondroitinases, labeled with 2-anthranilic acid-d4 (2-AA) and subjected to size exclusion chromatography with online electrospray ionization mass spectrometric detection in the negative ion mode. The method presented herein enabled simultaneous determination of sulfate position and uronic acid epimerization in juvenile bovine and adult human cartilage samples. The method was applied to a series of 13 adult human cartilage explants. Standard deviation of the mean for the measurements was 1.6 on average. Coefficients of variation were approximately 4% for all compositions of 40% or greater. These results show that the new method has sufficient accuracy to allow determination of topographical distribution of glycoforms in connective tissue.
Key words: cartilage / glycomics / glycosaminoglycan / mass spectrometry
None declared.