title: A cyclic disulfide peptide reproduces in solution the main structural features of a native antigenic site of foot-and-mouth disease virus.
abstract: A cyclic disulfide peptide corresponding to the G-H loop sequence 134-155 [replacement Tyr136 and Arg153 with Cys] of the capsid protein VP1 of foot-and-mouth disease virus (FMDV) isolate C-S8c1 was examined by proton 2D-NMR spectroscopy in water and in 25% HFIP/water. In water, NMR data supported the presence of a non-canonical turn in the central, conserved cell adhesion RGD motif and suggested the presence of a nascent helix in the C-terminal part, stabilized and slightly extended upon addition of 25% HFIP, a secondary structure stabilizing cosolvent. The formation of the C-terminal helix was evidenced by combined analysis of NOE connectivities, H alpha chemical shifts, 3JNH-H alpha coupling constants and amide temperature coefficients. Surprisingly, these global structural features of the cyclic peptide in solution show similarities to previous X-ray structure analysis of (a) a shortened linear peptide complexed with a antivirus antibody and (b) the G-H loop represented on the chemical reduced viral surface of a different serotype. Thus, even in entirely different biological environments the cyclic peptide reflect similar structural features, reinforcing the concept that this viral loop behaves as an independent structural and functional unit.
authors.affiliation: Department of Organic Chemistry, University of Barcelona, Spain.
authors.forename: T
authors.initials: T
authors.lastname: Haack
authors.forename: J A
authors.initials: JA
authors.lastname: Camarero
authors.forename: X
authors.initials: X
authors.lastname: Roig
authors.forename: M G
authors.initials: MG
authors.lastname: Mateu
authors.forename: E
authors.initials: E
authors.lastname: Domingo
authors.forename: D
authors.initials: D
authors.lastname: Andreu
authors.forename: E
authors.initials: E
authors.lastname: Giralt
mesh_terms: D000433:1-Propanol / Q000737:chemistry; D000595:Amino Acid Sequence; D002213:Capsid / Q000737:chemistry* / Q000276:immunology*; D036022:Capsid Proteins; D000939:Epitopes / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy / Q000379:methods; D008958:Models, Molecular; D008969:Molecular Sequence Data; D010456:Peptides, Cyclic / Q000737:chemistry* / Q000276:immunology; D020005:Propanols; D011487:Protein Conformation; D017433:Protein Structure, Secondary; D012997:Solvents; D013440:Sulfides / Q000737:chemistry; D013696:Temperature; D014867:Water; D006845:Hydrocarbons, Fluorinated
chemical_list: D000433:1-Propanol; D036022:Capsid Proteins; D000939:Epitopes; D010456:Peptides, Cyclic; D020005:Propanols; D012997:Solvents; D013440:Sulfides; D014867:Water; C442501:VP1 protein, Foot-and-mouth disease virus; C001337:hexafluoroisopropanol; D006845:Hydrocarbons, Fluorinated