Quantitative analysis of type I collagen fibril regulation by lumican and decorin using AFM

Abstract Lumican and decorin, two members of the small leucine-rich repeat proteoglycan (SLRP) family, have been implicated as regulators of collagen I fibril structure in different tissues. Both proteoglycans consist of a core protein and a glycosaminoglycan (GAG) chain, but quantitative information regarding the precise role of the protein and GAG moieties in regulating collagen structure is still limited. In this study, we used AFM imaging and a model system of aligned collagen I nanofibrils to investigate the role of lumican and decorin on collagen I fibril structure with high resolution. When co-assembled with collagen I, recombinant lumican or decorin proteins lacking the GAG chains decreased collagen fibril width to values below