IDURONIC ACID-RICH PROTEOGLYCANS (PG(IDOA)) AND HUMAN POSTBURN SCAR MATURATION - ISOLATION AND CHARACTERIZATION

Proteoglycans (PGs) were extracted from human hypertrophic and normal scar tissues from two different stages of maturation after burn injury , under dissociative conditions (4 M guanidinium chloride containing p roteinase inhibitors). The extracts were fractionated by ion-exchange chromatography, followed by ethanol precipitation, to give PG-containi ng iduronic acid (PG(IdoA)). The size of the PG(IdoA) decreased with t he maturation of scars. Glycosaminoglycan (GAG) chains from PG(IdoA) w ere released by alkaline borohydride treatment, and their M(r) values were evaluated by polyacrylamide gel electrophoresis. The M(r) values for PG(IdoA) protein cores of the hypertrophic scars (5+ years and 2-5 years) and normal scar (5+ years and 2-5 years) were 22.6, 25, 19 and 21 KDa, respectively. The iduronic acid content of PG(IdoA) from both types of scar increased in their maturation phase. The M(r) values of PG(IdoA) decreased with maturation. PG(IdoA) carried the sulfate grou p mainly attached al C-4 of the 2-amino-2-deoxy-D-galactose residue. T he NH2-terminal amino acid sequences of all the PG(IdoA) were similar to those of normal human skin or bone PG II (decorin) (i.e., lu-Ala-B- Gly-Ile-Gly-Pro-Glu-Val-Pro-Asp-Asp-Arg).