Interaction of decorin with CNBr peptides from collagens I and II. Evidence for multiple binding sites and essential lysyl residues in collagen.
Decorin is a small leucine-rich chondroitin/dermatan sulfate proteoglycan reported to interact with fibrillar collagens through its protein core and to localize at d and e bands of the collagen fibril banding pattern. Using a solid-phase assay, we have determined the interaction of peptides derived by CNBr cleavage of type I and type II collagen with decorin extracted from bovine tendon and its protein core and with a recombinant decorin preparation. At least five peptides have been found to interact with all three decorin samples. The interaction of peptides with tendon decorin has a dissociation constant in the nanomolar range. The triple helical conformation of the peptide trimeric species is a necessary requisite for the binding. All positive peptides have a region within the d and e bands of collagen fibrils. Two chemical derivatives of collagens and of positive peptides were prepared by N-acetylation and N-methylation of the primary amino group of Lys/Hyl side chains. Chemical modifications performed in mild conditions do not significantly alter the thermal stability of peptide trimeric species whereas they affect the interaction with decorin: N-acetylation eliminates both the positive charge and the binding to decorin, whereas N-methylation preserves the cationic character and modulates the binding. We conclude that decorin makes contacts with multiple sites in type I collagen and probably also in type II collagen and that some collagen Lys/Hyl residues are essential for the binding.
Tenni
Ruggero
R
Dipartimento di Biochimica A. Castellani, University of Pavia, Italy. rtenni@unipv.it
Viola
Manuela
M
Welser
Franz
F
Sini
Patrizia
P
Giudici
Camilla
C
Rossi
Antonio
A
Tira
M Enrica
ME
D001665:Binding Sites; D024042:Collagen Type I / Q000737:chemistry*; D024043:Collagen Type II / Q000737:chemistry*; D003488:Cyanogen Bromide; D058575:Decorin; D016326:Extracellular Matrix Proteins; D008239:Lysine; D010446:Peptide Fragments / Q000737:chemistry*; D011487:Protein Conformation; D011509:Proteoglycans / Q000737:chemistry*
D024042:Collagen Type I; D024043:Collagen Type II; D058575:Decorin; D016326:Extracellular Matrix Proteins; D010446:Peptide Fragments; D011509:Proteoglycans; D008239:Lysine; D003488:Cyanogen Bromide