The seeds of the passion fruit contain Passiflin, a novel dimeric antifungal protein. - GreenMedInfo Summary
Passiflin, a novel dimeric antifungal protein from seeds of the passion fruit.
Phytomedicine. 2009 Mar;16(2-3):172-80. Epub 2009 Feb 5. PMID: 19200704
The intent was to isolate an antifungal protein from seeds of the passion fruit (Passiflora edulis) and to compare its characteristics with other antifungal proteins and bovine beta-lactoglobulin in view of its N-terminal amino acid sequence similarity to beta-lactoglobulin. The isolation procedure entailed ion-exchange chromatography on Q-Sepharose, hydrophobic interaction chromatography on Phenyl-Sepharose, ion-exchange chromatography on DEAE-cellulose, and FPLC-gel filtration on Superdex 75. The isolated 67-kDa protein, designated as passiflin, exhibited an N-terminal amino acid sequence closely resembling that of bovine beta-lactoglobulin. It is the first antifungal protein found to have a beta-lactoglobulin-like N-terminal sequence. Its dimeric nature is rarely found in antifungal proteins. It impeded mycelial growth in Rhizotonia solani with an IC(50) of 16 microM and potently inhibited proliferation of MCF-7 breast cancer cells with an IC(50) of 15 microM. There was no cross-reactivity of passiflin with anti-beta-lactoglobulin antiserum. Intact beta-lactoglobulin lacks antifungal and antiproliferative activities and is much smaller in molecular size than passiflin. However, it has been reported that hydrolyzed beta-lactoglobulin shows antifungal activity. The data suggest that passiflin is distinct from beta-lactoglobulin.