Purification, characterization, and sequencing of a novel type of antimicrobial peptides, Fa-AMP1 and Fa-AMP2, from seeds of buckwheat (Fagopyrum esculentum Moench.).
Novel antimicrobial peptides (AMP), designated Fa-AMP1 and Fa-AMP2, were purified from the seeds of buckwheat (Fagopyrum esculentum Moench.) by gel filtration on Sephadex G75, ion-exchange HPLC on SP COSMOGEL, and reverse-phase HPLC. They were basic peptides having isoelectric points of over 10. Fa-AMP1 and Fa-AMP2 had molecular masses of 3,879 Da and 3,906 Da on MALDI-TOF MS analysis, and their extinction coefficients in 1% aqueous solutions at 280 nm were 42.8 and 38.9, respectively. Half of all amino acid residues of Fa-AMP1 and Fa-AMP2 were cysteine and glycine, and they had continuous sequences of cysteine and glycine. The concentrations of peptides required for 50% inhibition (IC50) of the growth of plant pathogenic fungi, and Gram-positive and -negative bacteria were 11 to 36 microg/ml. The structural and antimicrobial characteristics of Fa-AMPs indicated that they are a novel type of antimicrobial peptides belonging to a plant defensin family.
Fujimura
Masatoshi
M
Department of Biochemical Science and Technology, Faculty of Agriculture, Kagoshima University, 1-21-24 Korimoto, Kagoshima 890-0065, Japan. stu3008@chem.agri.kagoshima-u.ac.jp
Minami
Yuji
Y
Watanabe
Keiichi
K
Tadera
Kenjiro
K
D000192:Actinomycetales / Q000187:drug effects; D000595:Amino Acid Sequence; D000596:Amino Acids / Q000737:chemistry; D000890:Anti-Infective Agents / Q000302:isolation & purification / Q000494:pharmacology; D000935:Antifungal Agents / Q000302:isolation & purification / Q000494:pharmacology; D023082:Defensins / Q000737:chemistry* / Q000235:genetics / Q000302:isolation & purification / Q000494:pharmacology*; D019612:Fagopyrum / Q000737:chemistry*; D005670:Fusarium / Q000187:drug effects; D005848:Geotrichum / Q000187:drug effects; D006090:Gram-Negative Bacteria / Q000187:drug effects; D008969:Molecular Sequence Data; D008970:Molecular Weight; D010940:Plant Proteins / Q000737:chemistry* / Q000235:genetics / Q000302:isolation & purification / Q000494:pharmacology*; D012639:Seeds / Q000737:chemistry; D016415:Sequence Alignment; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / Q000379:methods
D000596:Amino Acids; D000890:Anti-Infective Agents; D000935:Antifungal Agents; D023082:Defensins; D010940:Plant Proteins