CHONDROITINASE ABC-RESISTANT SULFATED TRISACCHARIDES ISOLATED FROM DIGESTS OF CHONDROITIN DERMATAN SULFATE CHAINS/

Four kinds of sulfated trisaccharides resistant to chondroitinase ABC were isolated after chondroitinase B or ABC treatment of dermatan sulf ate or various chondroitin sulfate isomers, respectively. Their compos ition was determined by chemical analysis and fast atom bombardment-ma ss spectrometry. Their structures were characterized by chondroitinase ACII digestion in conjunction with HPLC, and 500-MHz one- and two-dim ensional H-1 NMR spectroscopy. All the four trisaccharides have in com mon the core saccharide sequence, alpha-L-Delta(4,5)HexpA-(1 --> 3)-be ta-D-GalpNAc(1 --> 4)-D-GlcpA. A monosulfated component isolated from shark scapular cartilage chondroitin sulfate C or bovine aorta dermata n sulfate was elucidated as alpha-L-Delta(4,5)HexpA-(1 --> 3)-beta-D-G alpNAc6SO(3)(-)-(1 -->)-D-GlcpA or alpha-L-Delta(4,5)HexpA-(1 --> 3)-b eta-D-GalpNAc4SO(3)(-)-(1 --> 4)-D-GlcpA, respectively. A disulfated c omponent obtained from shark scapular cartilage chondroitin sulfate C or squid cartilage chondroitin sulfate E was identified as alpha-L-Del ta(4,5)HexpA2SO(3)(-)-(1 --> 3)-beta-D-GalpNAc6SO(3)(-)-(1 --> 4)-D-Gl cpA or alpha-L-Delta(4,5)HexpA-(1 --> 3)-beta-D-GalpNAc4SO(3)(-)6SO(3) (-)-(1 --> 4)-D-GlcpA, respectively. These trisaccharides are derived from the reducing termini of the parent polysaccharides. some of the t risaccharides could be derived from the reducing termini exposed by th e peeling reaction during the alkaline treatment while some others may represent the cleavage sites exposed by tissue endo-beta-D-glucuronid ase(s), indicating the presence of such enzyme(s) which may release ch ondroitin/dermatan sulfate fragments from proteoglycans.