title: Molecular scaffold of a new pokeweed antifungal peptide deduced by 1H nuclear magnetic resonance.
abstract: The antifungal peptide from seeds of Phytolacca americana (Pokeweed), designated PAFP-S hereinafter, is a recently found cationic peptide which consists of 38 amino acid residues and exhibits a broad spectrum of antifungal activity, including inhibition of certain saprophytic fungi and some plant pathogens. The secondary structure and three cysteine pairings have been investigated by 1H NMR analysis. The results show that the molecular scaffold of PAFP-S features a triple-stranded antiparallel beta-sheet knotted by a typical disulfide bridge motif, which characterizes the knottin fold. CD spectroscopy indicates a high stability of the molecule in solution. Therefore, PAFP-S should be a new member of the knottin structural family and the first antifungal peptide that adopts the knottin-like fold.
authors.affiliation: Laboratory of Molecular Biophysics, Institute of Biophysics, Chinese Academy of Science, 15 Datun Road, Chaoyang District, 100101, Beijing, People's Republic of China.
authors.forename: G H
authors.initials: GH
authors.lastname: Gao
authors.forename: W
authors.initials: W
authors.lastname: Liu
authors.forename: J X
authors.initials: JX
authors.lastname: Dai
authors.forename: J F
authors.initials: JF
authors.lastname: Wang
authors.forename: Z
authors.initials: Z
authors.lastname: Hu
authors.forename: Y
authors.initials: Y
authors.lastname: Zhang
authors.forename: D C
authors.initials: DC
authors.lastname: Wang
mesh_terms: D020816:Amino Acid Motifs; D000595:Amino Acid Sequence; D000935:Antifungal Agents / Q000737:chemistry*; D002942:Circular Dichroism; D004220:Disulfides; D006863:Hydrogen-Ion Concentration; D009682:Magnetic Resonance Spectroscopy; D008969:Molecular Sequence Data; D010455:Peptides / Q000737:chemistry*; D029604:Phytolacca americana / Q000737:chemistry*; D011487:Protein Conformation; D017433:Protein Structure, Secondary; D017386:Sequence Homology, Amino Acid
chemical_list: D000935:Antifungal Agents; D004220:Disulfides; D010455:Peptides