Dermatan sulfate (DS)
proteoglycans (PGs) were extracted from human post-
burn scar (Sc) tissues with 4M
guanidinium chloride and isolated from the extracts by
DEAE-cellulose chromatography and by differential
ethanol precipitation. The DS.PGs were further purified by
Sepharose CL-6B column chromatography. The average molecular weight (Mr) of
hypertrophic scar (HSc) tissue DS.PGs was 39,000 based on sedimentation equilibrium measurements. Alkaline
borohydride treatment of DS.PGs liberated
glycosaminoglycan (GAG) chains and the presence of
xylitol indicated that these chains were attached to
protein core by xylosyl residues. The average Mr of the DS.GAG chain from HSc and normal
scar (NSc) samples were 23,500 and 20,000 respectively. After digestion of the HSc and NSc, DS.PGs with
chondroitinase ABC in the presence of
proteinase inhibitors, two
peptide components with Mr values of 21,500 and 17,000 were detected by SDS-
polyacrylamide gel electrophoresis using reducing conditions. Analysis of the
protein core fractions derived from NSc and HSc DS.PGs by
Sepharose CL-6B column chromatography showed the presence of a single NH2-terminal
amino acid (
aspartic acid) and also that the fractions with different KAV values had an identical NH2-terminal sequence (A1-A5). The A1-A23 sequence of NSc DS.PG (major fraction, C): NH2Asp-Glu-Ala-O-Gly-Ile-Gly-Pro-Glu-Val-Pro-Asp-Asp-Arg-Asp-Phe-G lu-
Pro- Ser-
Leu-Gly-
Pro-Val was the same as reported for a DS.PG isolated from human fetal membrane (HFM) tissue (Brennan et al., 1984). ELISA inhibition assay using
monoclonal antibodies raised in rabbit against the NH2-terminal
peptide (containing 15
amino acids) of human fetal membrane tissue were found to cross-react with HSc and NSc DS.PGs.
Monoclonal antibodies to bovine skin DS.PGs
protein core (Pearson et al., 1983) did not show any cross-reactivity with
scar DS.PGs. These results show that the
scar DS.PGs described here are different from normal bovine skin DS.PGs in the size and type of the
protein core, and that in all the samples, the
peptide components have the same NH2-terminal amino acid sequence.