Acceleracted publication - Decorin binds near the C terminus of type I collagen

Decorin belongs to a family of small leucine-rich proteoglycans that are di rectly involved in the control of matrix organization and cell growth, Gene tic evidence indicates that decorin is required for the proper assembly of collagenous matrices. Here, we sought to establish the precise binding site of decorin on type I collagen. Using rotary shadowing electron microscopy and photoaffinity labeling, we mapped the binding site of decorin protein c ore to a narrow region near the C terminus of type I collagen. This region is located within the cyanogen bromide peptide fragment alpha 1(I) CB6 and is similar to 25 nm from the C terminus, in a zone that coincides with the c(1) band of the collagen fibril D-period. This location is very close to o ne of the major intermolecular cross-linking sites of collagen heterotrimer s. Thus, decorin protein core possesses a unique binding specificity that c ould potentially regulate collagen fibril stability.