Eryngin, a novel antifungal peptide from fruiting bodies of the edible mushroom Pleurotus eryngii

An antifungal peptide with a molecular mass of 10k Da was isolated from fruiting bodies of the mushroom Pleurotus eryngii. The peptide, designated as eryngin, inhibited mycelial growth in Fusarium oxysporum and Mycosphaerella arachidicola. It was unadsorbed on DEAE-cellulose and adsorbed on Affi-gel blue gel and S-Sepharose. Its N-terminal sequence demonstrated some similarity to the antifungal protein from the mushroom Lyophyllum shimeiji and little resemblance to thaumatin and thaumatin-like proteins.     

Isolation and characterization of luffacylin,a ribosome inactivating peptide with anti-fungal activity from sponge gourd (Luffa cylindrica) seeds

A purification scheme involving ion exchange chromatography on DEAE-cellulose, affinity chromatography on Affi-gel blue gel, and ion exchange chromatography on CM-Sepharose and Mono S was employed to isolate a peptide with a molecular weight of 7.8kDa from sponge gourd seeds. The peptide, which was designated luffacylin, exhibited an N-terminal sequence with pronounced resemblance to that of the 6.5kDa arginine-glutamate rich polypeptide previously isolated from sponge gourd seeds. Luffacylin inhibited translation in a rabbit reticulocyte lysate system with an IC(50) of 140pM and reacted positively in the N-glycosidase assay for ribosome inactivating proteins. Luffacylin exerted anti-fungal activity against Mycosphaerella arachidicola and Fusarium oxysporum.     

First isolation of an antifungal lipid transfer peptide from seeds of a Brassica species

An antifungal peptide with a molecular mass of 9412 and an N-terminal sequence exhibiting notable homology to those of lipid transfer proteins was isolated from seeds of the vegetable Brassica campestris. The purification protocol entailed ion exchange chromatography on Q-Sepharose, affinity chromatography on Affi-gel blue gel, ion exchange chromatography by fast protein liquid chromatography (FPLC) on Mono S, and gel filtration by FPLC on a Superdex peptide column. The antifungal peptide was adsorbed on Affi-gel blue gel and Mono S. It inhibited mycelial growth in Fusarium oxysporum and Mycosphaerella arachidicola with an IC(50) value of 8.3 microM and 4.5 microM, respectively. It exhibited dose-dependent binding to lyso-alpha-lauroyl phosphatidylcholine. The present findings constitute the first report on a non-specific lipid transfer protein from the seeds of a Brassica species.     

Isolation of allicepin, a novel antifungal peptide from onion (Allium cepa) bulbs.

From the bulbs of the onion Allium cepa, a novel antifungal peptide distinct from the antimicrobial peptide previously reported from onion seeds was isolated. The antifungal peptide, designated allicepin, was purified with a procedure that involved aqueous extraction, ion exchange chromatography on DEAE-cellulose, affinity chromatography on Affi-gel blue gel and FPLC-gel filtration on Superdex 75. Allicepin was unadsorbed on DEAE-cellulose and adsorbed on Affi-gel blue gel. The molecular weight of allicepin was estimated to be 10 K by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and gel filtration on Superdex 75. Allicepin exerted an inhibitory activity on mycelial growth in several fungal species including Botrytis cinerea, Fusarium oxysporum, Mycosphaerella arachidicola and Physalospora piricola.     

Pleurostrin, an antifungal peptide from the oyster mushroom

A 7kDa peptide, with inhibitory activity on mycelial growth in the fungi Fusaerium oxysporum, Mycosphaerella arachidicola and Physalospora piricola, was isolated from fresh fruiting bodies of the oyster mushroom. The isolation procedure entailed extraction with an aqueous buffer, ion exchange chromatography on DEAE-cellulose, affinity chromatography on Affi-gel blue gel and gel filtration by fast protein liquid chromatography on Superdex 75. The protein was unadsorbed on DEAE-cellulose and adsorbed on Affi-gel blue gel. It demonstrated an N-terminal sequence different from known antifungal proteins and peptides.