An antifungal peptide from Phaseolus vulgaris cv. brown kidney bean.
A 5.4-kDa antifungal peptide, with an N-terminal sequence highly homologous to defensins and inhibitory activity against Mycosphaerella arachidicola (IC(50)= 3 μM), Setospaeria turcica and Bipolaris maydis, was isolated from the seeds of Phaseolus vulgaris cv. brown kidney bean. The peptide was purified by employing a protocol that entailed adsorption on Affi-gel blue gel and Mono S and finally gel filtration on Superdex 75. The antifungal activity of the peptide against M. arachidicola was stable in the pH range 3-12 and in the temperature range 0°C to 80°C. There was a slight reduction of the antifungal activity at pH 2 and 13, and the activity was indiscernible at pH 0, 1, and 14. The activity at 90°C and 100°C was slightly diminished. Deposition of Congo red at the hyphal tips of M. arachidicola was induced by the peptide indicating inhibition of hyphal growth. The lack of antiproliferative activity of brown kidney bean antifungal peptide toward tumor cells, in contrast to the presence of such activity of other antifungal peptides, indicates that different domains are responsible for the antifungal and antiproliferative activities.
School of Biomedical Sciences, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong, China.
Yau Sang
YS
Chan
Jack Ho
JH
Wong
Evandro Fei
EF
Fang
Wen Liang
WL
Pan
Tzi Bun
TB
Ng
D000595:Amino Acid Sequence; D000935:Antifungal Agents / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D001203:Ascomycota / Q000187:drug effects / Q000254:growth & development; D003224:Congo Red; D023082:Defensins / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology; D004591:Electrophoresis, Polyacrylamide Gel; D006863:Hydrogen-Ion Concentration; D020128:Inhibitory Concentration 50; D018613:Microscopy, Confocal; D008856:Microscopy, Fluorescence; D008969:Molecular Sequence Data; D008970:Molecular Weight; D010455:Peptides / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D027805:Phaseolus / Q000737:chemistry*; D010940:Plant Proteins / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D055550:Protein Stability; D020539:Sequence Analysis, Protein; D017386:Sequence Homology, Amino Acid; D013696:Temperature
D000935:Antifungal Agents; D023082:Defensins; D010455:Peptides; D010940:Plant Proteins; D003224:Congo Red