Collagen like model peptide (T3-785 peptide)
Synthetic peptide (containing human type III collagen sequence)
Collagen is a main component of connective tissues such as bone and cartilage, and the collagen fibril makes the tissues stiff and elastic. Collagen also forms an extracellular scaffold, extracellular matrix, where various proteins bind and regulate various physiological functions; integrin mediated contact signaling, collagenase induced chemotaxis, and so on.
Three collagen peptides form a rod-like triple supercoil. The peptides require triplet repeat sequence containing glycine(Gly) every third residue, (X1-X2-Gly)n. X1 and X2 are most frequently imino acids Proline(Pro) and Hydroxyproline(Hyp) respectively, however how X1 and X2 residues affect the local structure of the helix was not fully understood. To address this question, Kramer et al. created T3-785 peptide, (Pro-Hyp-Gly)3-Ile-Thr-Gly-Ala-Arg-Gly-Leu-Ala-Gly-Pro-Hyp-Gly-(Pro-Hyp-Gly)3, as a collagen-like model peptide, which includes collagenase recognition sequence of human type III capped with (Pro-Hyp-Gly)3 in the N- and C-terminus. They compared the structure of coils between imino acid-rich N- and C- terminal and full amino acid collagenase recognition sequence. Their findings were following.
Protein Data Bank (PDB)
Kramer, R.Z. Bella, J. Mayville, P. Brodsky, B. Berman, H.M.; "Sequence dependent conformational variations of collagen triple-helical structure."; Nature Struct. Biol.; (1999) 6:454-457 PubMed:10331873.
author: Daisuke Ino