Keywords: Collagen, Proline, Protein Structure Stability, Triple Helix, X-Ray Structure, Collagen Fibril, Glycine, Hydroxyproline, Polypeptide, Article, Crystal Structure, Diffraction, Electricity, Gravity, Molecular Model, Priority Journal, Protein Assembly, Protein Stability, Synchrotron Radiation, Crystallization, Crystallography, Hydrogen Bonding, Oligopeptides, Protein Conformation,
Affiliations: *** IBB - CNR ***
Centro di Studio di Biocristallografia, CNR, I-80134 Napoli, Italy
Dipartimento di Chimica, Università degli Studi di Napoli Federico II, I-80126, Napoli, Italy
CEINGE, Biotecnologie Avanzate Scarl, Napoli, Italy
References: Not available.
Crystal structure of the collagen triple helix model [(Pro-Pro-Gly)10]3
The first report of the full-length structure of the collagen-like polypeptide [(Pro-Pro-Gly)10]3 is given. This structure was obtained from crystals grown in a microgravity environment, which diffracted up to 1.3 Å, using synchrotron radiation. The final model, which was refined to an Rfactor of 0.18, is the highest-resolution description of a collagen triple helix reported to date. This structure provides clues regarding a series of aspects related to collagen triple helix structure and assembly. The strict dependence of proline puckering on the position inside the Pro-Pro-Gly triplets and the correlation between backbone and side chain dihedral angles support the propensity-based mechanism of triple helix stabilization/destabilization induced by hydroxyproline. Furthermore, the analysis of [(Pro-Pro-Gly)10]3 packing, which is governed by electrostatic interactions, suggests that charges may act as locking features in the axial organization of triple helices in the collagen fibrils.
Crystal structure of the collagen triple helix model [(Pro-Pro-Gly)10]3