Characterization of two novel defense peptides from pea (Pisum sativum) seeds.
A fraction that possesses antifungal activity against Aspergillus niger has been isolated from seeds of the pea (Pisum sativum) by ammonium sulfate fractionation followed by gel filtration on Sephadex G-75. On further purification by reverse-phase high performance liquid chromatography, two small cysteine-rich polypeptides were obtained (Psd1 and Psd2). They are localized primarily in vascular bundles and epidermis tissues of pea pods and exhibit high antifungal activity toward several fungi, displaying IC(50) values ranging from 0.04 to 22 microg/ml. This inhibitory activity decreases when A. niger growth medium is supplemented with cations such as Ca(2+), Mg(2+), Na(+), and K(+). Although the primary sequence of both Psd1 and Psd2 shows homology with other plant defensins, they cannot easily be assigned to any established group.
Almeida
M S
MS
Departamento de Bioqu¿imica M¿edica, Universidade Federal do Rio de Janeiro, CEP, Rio de Janeiro, RJ, 21941-590, Brasil.
Cabral
K M
KM
Zingali
R B
RB
Kurtenbach
E
E
D000595:Amino Acid Sequence; D000935:Antifungal Agents / Q000494:pharmacology; D015153:Blotting, Western; D002118:Calcium / Q000378:metabolism; D002850:Chromatography, Gel; D002851:Chromatography, High Pressure Liquid; D003545:Cysteine / Q000737:chemistry; D018076:DNA, Complementary / Q000378:metabolism; D023082:Defensins; D004305:Dose-Response Relationship, Drug; D004591:Electrophoresis, Polyacrylamide Gel; D020128:Inhibitory Concentration 50; D007477:Ions; D008274:Magnesium / Q000378:metabolism; D008856:Microscopy, Fluorescence; D008969:Molecular Sequence Data; D018532:Pisum sativum / Q000737:chemistry*; D010455:Peptides / Q000737:chemistry*; D010936:Plant Extracts / Q000737:chemistry; D010940:Plant Proteins / Q000737:chemistry* / Q000378:metabolism / Q000494:pharmacology; D011188:Potassium / Q000378:metabolism; D011506:Proteins / Q000737:chemistry* / Q000494:pharmacology; D012333:RNA, Messenger / Q000378:metabolism; D017386:Sequence Homology, Amino Acid; D012964:Sodium / Q000378:metabolism; D013997:Time Factors; D014357:Trypsin / Q000378:metabolism; D015003:Yeasts / Q000187:drug effects
D000935:Antifungal Agents; D018076:DNA, Complementary; D023082:Defensins; D007477:Ions; D010455:Peptides; D010936:Plant Extracts; D010940:Plant Proteins; D011506:Proteins; D012333:RNA, Messenger; C410643:defensin 1, Pisum sativum; C410642:defensin 2 protein, Pisum sativum; D012964:Sodium; D014357:Trypsin; D008274:Magnesium; D003545:Cysteine; D011188:Potassium; D002118:Calcium