Purification and characterization of an antifungal PR-5 protein from pumpkin leaves.
A 28-kDa antifungal PR-5 protein (PLTP) was purified from pumpkin leaves to homogeneity by using ammonium sulfate fractionation, a regenerated chitin column, and reversed-phase column chromatographies on butyl-Toyopearl and HPLC C18 columns. Analysis of 14 N-terminal amino acid sequences of PLTP shows 100% sequence identity to those of two PR-5 proteins, NP24 from tomatoes and AP24 from tobacco. The identical sequence also exhibited high amino acid sequence homology to that of an osmotin-like protein (OLP; 71%) from tobacco cells and thaumatin (64%), a sweet-tasting protein of Thaumatococcus danielli Bench. When the PLTP was immuno-blotted with antiserum raised against the tobacco OLP, the OLP antibody specifically cross-reacted with the PLTP, suggesting that they share several common epitopes in their tertiary structure of the proteins. The purified PLTP rapidly lyzed hyphal tips of Neurospora crassa at a concentration greater than 200 nM and significantly inhibited the fungal growth of Fusarium oxysporum in an agar-disc plate at a concentration greater than 2 microM. It also shows a synergistic effect with nikkomycin, a chitin synthase inhibitor, for the growth inhibition of Candida albicans.
Cheong
N E
NE
Department of Biochemistry, Gyeongsang National University, Chinju, Korea.
Choi
Y O
YO
Kim
W Y
WY
Bae
I S
IS
Cho
M J
MJ
Hwang
I
I
Kim
J W
JW
Lee
S Y
SY
D000595:Amino Acid Sequence; D000617:Aminoglycosides; D000900:Anti-Bacterial Agents / Q000008:administration & dosage; D000935:Antifungal Agents / Q000008:administration & dosage / Q000302:isolation & purification* / Q000494:pharmacology; D002176:Candida albicans / Q000187:drug effects; D004357:Drug Synergism; D005638:Fruit / Q000737:chemistry* / Q000235:genetics; D005656:Fungal Proteins / Q000235:genetics / Q000302:isolation & purification* / Q000494:pharmacology; D005670:Fusarium / Q000187:drug effects; D009492:Neurospora crassa / Q000187:drug effects; D010940:Plant Proteins / Q000235:genetics / Q000302:isolation & purification* / Q000494:pharmacology; D017386:Sequence Homology, Amino Acid
D000617:Aminoglycosides; D000900:Anti-Bacterial Agents; D000935:Antifungal Agents; D005656:Fungal Proteins; D010940:Plant Proteins; C053376:pathogenesis-related proteins, plant; C011952:nikkomycin