Crystal and molecular structure of a collagen-like peptide at 1.9Å resolution. Science 266: 75-81

Department of Chemistry, Rutgers University, New Brunswick, NJ 08855.
Science (Impact Factor: 33.61). 11/1994; 266(5182):75-81. DOI: 10.1126/science.7695699
Source: PubMed

ABSTRACT The structure of a protein triple helix has been determined at 1.9 angstrom resolution by x-ray crystallographic studies of a collagen-like peptide containing a single substitution of the consensus sequence. This peptide adopts a triple-helical structure that confirms the basic features determined from fiber diffraction studies on collagen: supercoiling of polyproline II helices and interchain hydrogen bonding that follows the model II of Rich and Crick. In addition, the structure provides new information concerning the nature of this protein fold. Each triple helix is surrounded by a cylinder of hydration, with an extensive hydrogen bonding network between water molecules and peptide acceptor groups. Hydroxyproline residues have a critical role in this water network. The interaxial spacing of triple helices in the crystal is similar to that in collagen fibrils, and the water networks linking adjacent triple helices in the crystal structure are likely to be present in connective tissues. The breaking of the repeating (X-Y-Gly)n pattern by a Gly-->Ala substitution results in a subtle alteration of the conformation, with a local untwisting of the triple helix. At the substitution site, direct interchain hydrogen bonds are replaced with interstitial water bridges between the peptide groups. Similar conformational changes may occur in Gly-->X mutated collagens responsible for the diseases osteogenesis imperfecta, chondrodysplasias, and Ehlers-Danlos syndrome IV.

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    • "Collagens can be divided into several families or groups based on their exon structure, containing several homologous genes encoding polypeptides that have domains with similar sequences. All collagens have domains with a triple helical conformation (Bella et al., 1994) and are a major constituent of connective tissue. Collagen fibrils composed primarily of type II and XI collagen provide a structural framework to hyaline cartilage (Li et al., 2007), and type I/III and V collagens are a major constituent of skin, tendon, ligaments and bone, demonstrating how the major constituents of the joint require collagen for their structural integrity. "
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    • "Recently, proline catabolism has gained attention as one such pathway, particularly under nutrient stress [11] [12] [15]. Proline and hydroxyproline comprise $ 20% of the amino acids in collagen [16], the main constituent of the extracellular matrix. Collagen Contents lists available at ScienceDirect journal homepage: "
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    12/2014; 2(1). DOI:10.1016/j.redox.2014.07.003
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    • "Studies of docking of capsaicin with peptides in triple-helical collagen molecules X-ray crystal structures of selected collagen model peptides were obtained from the Protein Data Bank (PDB; PDB IDs: 1CAG, 1QSU, 2DRT, 1Q7D) (Bella et al. 1994). The structures were prepared by use of the protein-preparation wizard of the software Discovery Studio 4.0. "
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