RESUMO
Aims: To isolate and characterize an antimicrobial peptide from fruiting bodies of Lentinus squarrosulus Mont., the Thai common edible mushroom. Methodology and results: Solid ammonium sulfate at 40-80% (w/v) final concentration was utilized to precipitate the proteins and further purified by ion exchange chromatography on DEAE-cellulose and gel filtration chromatography on Sephadex G-25. The peptide was adsorbed on DEAE-cellulose and Sephadex G-25. It appeared as a single band with a molecular mass of about 17 kDa (kilodalton) in sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Further investigation of antimicrobial properties of purified peptide revealed that it has no activity against both Gram positive and Gram negative bacteria. However, it exhibited strong antifungal activity against various species of fungal pathogen of human. Among the high sensitive strains, Trichophyton mentagrophytes, T. rubrum, and Candida tropicalis are clinical isolates. Moreover, the potency was found to be concentration dependent and comparable with Ketoconazole, the commercial antifungal drug. Conclusion, significance and impact study: In this work, the novel bioactive peptide from fruiting bodies of L. squarrosulus Mont. has been isolated. It shows potent activity against various clinical isolates of fungal pathogen of human. It may have potential for pharmaceutical application.