Untitled

Abstract

Dermatan sulfate was partially depolymerized with chondroitin ABC lyase to obtain an oligosaccharide mixture from which an unsaturated disulfated tetrasaccharide was purified and characterized using nuclear magnetic resonance spectroscopy and electrospray ionization mass spectrometry. Chemical removal of the unsaturated uronate residue with mercuric acetate, followed by de-4-O-sulfation with arylsulfatase B (N-acetylgalactosamine 4-sulfatase) and N- acetylhexosaminidase catalyzed removal of the 2-acetamido-2-deoxy-D-galactospyranosyl residue at the non-reducing end afforded a monosulfated disaccharide of the structure alpha-L-idopyranosyluronic acid (1-->3)-alpha,beta-D-2-acetamido-2-deoxy-4-O-sulfo galactopyranose. This monosulfated disaccharide serves as a substrate for mammalian alpha-L-iduronidase as demonstrated using fluorophore assisted carbohydrate electrophoresis.

Proteoglycan sequence

“…4D). 64 The limitations of these middledown approaches include: (1) no information is provided on the context of placement within the intact GAG chain of the oligosaccharide being sequenced; (2) the maximum size of GAG-derived oligosaccharide that can be purified is usually ooctadecasaccharide; and (3) the quality of the sequencing data are dependent on the high specificity of the exoenzymes utilized and the resolution of the PAGE separation through the entire size range of the sequencing experiment. Nuclear magnetic resonance (NMR) spectroscopy for sequence determination NMR spectroscopy is sensitive to structural changes making it an important technique for GAG sequence analysis.…”

Carbohydrate post-glycosylational modifications

“…56 Enzymatic approaches using N-acetylgalactosamine 4-sulfatase (arylsulfatase B) have been applied in the de-sulfonation of 4S of the non-reducing terminal GalNAc residue of DS disulfated trisaccharide to afford monosulfated trisaccharide, which can be further converted to monosulfated disaccharide IdoAa1,3GalNAc(4S) using Nacetylhexosaminidase to provide a substrate for a-L-iduronidase (Scheme 2). 57 Chemical synthesis of DS oligosaccharides has also been reported in the last decade. 58 As L-IdoA is considered as a poor acceptor in the glycosylation with D-GalN donors, the strategy of using L-IdoA derivatives instead of L-IdoA as acceptors is often adopted in the synthesis of DS oligosaccharides.…”