title: Stabilization of triple-helical structures of collagen peptides containing a Hyp-Thr-Gly, Hyp-Val-Gly, or Hyp-Ser-Gly sequence.
abstract: The single-crystal structures of three collagen-like host-guest peptides, (Pro-Pro-Gly)(4) -Hyp-Yaa-Gly-(Pro-Pro-Gly)(4) [Yaa = Thr, Val, Ser; Hyp = (4R)-4-hydroxyproline] were analyzed at atomic resolution. These peptides adopted a 7/2-helical structure similar to that of the (Pro-Pro-Gly)(9) peptide. The stability of these triple helices showed a similar tendency to that observed in Ac-(Gly-Hyp-Yaa)(10) -NH(2) (Yaa = Thr, Val, Ser) peptides. On the basis of their detailed structures, the differences in the triple-helical stabilities of the peptides containing a Hyp-Thr-Gly, Hyp-Val-Gly, or Hyp-Ser-Gly sequence were explained in terms of van der Waals interactions and dipole-dipole interaction between the Hyp residue in the X position and the Yaa residue in the Y position involved in the Hyp(X):Yaa(Y) stacking pair. This idea also explains the inability of Ac-(Gly-Hyp-alloThr)(10) -NH(2) and Ac-(Gly-Hyp-Ala)(10) -NH(2) peptides to form triple helices. In the Hyp(X):Thr(Y), Hyp(X):Val(Y), and Hyp(X):Ser(Y) stacking pairs, the proline ring of the Hyp residues adopts an up-puckering conformation, in agreement with the residual preference of Hyp, but in disagreement with the positional preference of X in the Gly-Xaa-Yaa sequence.
authors: Department of Macromolecular Science, Graduate School of Science, Osaka University, Osaka 560-0043, Japan. okuyamak@chem.sci.osaka-u.ac.jp
authors: Kenji
authors: K
authors: Okuyama
authors: Keita
authors: K
authors: Miyama
authors: Tatsuya
authors: T
authors: Morimoto
authors: Kouichi
authors: K
authors: Masakiyo
authors: Kazunori
authors: K
authors: Mizuno
authors: Hans Peter
authors: HP
authors: Bächinger
mesh_terms: D000595:Amino Acid Sequence; D002942:Circular Dichroism; D003094:Collagen / Q000737:chemistry*; D003460:Crystallization; D018360:Crystallography, X-Ray / Q000379:methods; D005998:Glycine / Q000737:chemistry; D006909:Hydroxyproline / Q000737:chemistry; D008968:Molecular Conformation; D008969:Molecular Sequence Data; D010455:Peptides / Q000737:chemistry*; D011392:Proline / Q000737:chemistry; D011487:Protein Conformation; D017433:Protein Structure, Secondary; D017386:Sequence Homology, Amino Acid; D012694:Serine / Q000737:chemistry; D013912:Threonine / Q000737:chemistry; D014633:Valine / Q000737:chemistry
chemical_list: D010455:Peptides; D013912:Threonine; D012694:Serine; D003094:Collagen; D011392:Proline; D014633:Valine; D006909:Hydroxyproline; D005998:Glycine