title: Compressibility and elasticity of amphiphilic and acidic β-sheet peptides at the air-water interface.
abstract: Grazing incidence X-ray diffraction measurements were performed on monolayer films of three amphiphilic and acidic β-sheet peptides having the general sequence Pro-Y-(Z-Y)(5)-Pro, with Y = Asp or Glu and Z = Phe or Leu denoted, P(FD)-5, P(LE)-5, P(LD)-5, and the 1:1 molar ratio mixture of P(LD)-5 and P(LE)-5. The crystalline domains of these peptides exhibited compressibility and elasticity of the crystalline unit cell indicated by changes in diffraction patterns on compression. Higher compressibility values appeared to be associated with more favorable cross-strand interactions between peptides with the larger side chains, whereas P(LD)-5, decorated by the smaller side chain amino acids, exhibited the lowest crystalline compressibility. Diffraction patterns provided evidence for a new subunit cell generated by the pleated β-strand motif in an apparently favorable mode of cross-strand intermolecular packing in β-sheets. The study contributes to the understanding of β-sheet flexibility at interfaces with relevance to natural proteins and designed biomaterials composed of β-sheet peptides.
authors.affiliation: Avram and Stella Goldstein-Goren Department of Biotechnology Engineering and the Ilze Katz Institute for Nanoscale Technology, Ben-Gurion University of the Negev, P.O. Box 653, Beer-Sheva 84105, Israel.
authors.forename: Vladimir
authors.initials: V
authors.lastname: Vaiser
authors.forename: Hanna
authors.initials: H
authors.lastname: Rapaport
mesh_terms: D000388:Air; D000595:Amino Acid Sequence; D006860:Hydrogen Bonding; D057927:Hydrophobic and Hydrophilic Interactions; D010455:Peptides / Q000737:chemistry*; D017433:Protein Structure, Secondary; D014867:Water / Q000737:chemistry*; D014961:X-Ray Diffraction
chemical_list: D010455:Peptides; D014867:Water