ROLE OF DECORIN ON IN-VITRO FIBRILLOGENESIS OF TYPE-I COLLAGEN

Tendon and corneal decorins are differently iduronated dermatan sulpha te/proteoglycan (DS/PG) and the biochemical parameter that differentia tes type I collagens is the hydroxylysine glycoside content. We have e xamined the effect of tendon and corneal decorins on the individual ph ases (tlag, dA/dt) of differently glycosylated type I collagens fibril formation, at molar ratios PG: collagen monomer ranging from 0.15:1 t o 0.45:1. The results obtained indicate that decorins exert a differen t effect on the individual phases of fibril formation, correlated to t he degree of glycosylation of collagen: at the same PG: collagen ratio the fibril formation of highly glycosylated corneal collagen is more efficiently inhibited than that of the poorly glycosylated one (tendon ). Moreover tendon and corneal decorins exert a higher control on the fibrillogenesis of homologous collagen with respect to the heterologou s one. These data suggest a possible tissue-specificity of the interac tion decorin/type I collagen correlated to the structure of the PG and collagen present in extracellular matrices.