Cordymin, an antifungal peptide from the medicinal fungus Cordyceps militaris

Abstract 

Cordymin, an antifungal peptide with a molecular mass of 10,906Da and an N-terminal amino acid sequence distinct from those of previously reported proteins, was purified from the medicinal mushroom Cordyceps militaris. The isolation protocol comprised ion exchange chromatography of the aqueous extract on SP-Sepharose and Mono S and gel filtration on Superdex 75 by a fast protein liquid chromatography system. Cordymin was adsorbed on both cation exchangers. The peptide inhibited mycelial growth in Bipolaris maydis, Mycosphaerella arachidicola, Rhizoctonia solani and Candida albicans with an IC₅₀ of 50μM, 10μM, 80μM, and 0.75mM, respectively. However, there was no effect on Aspergillus fumigatus, Fusarium oxysporum and Valsa mali when tested up to 2mM. The antifungal activity of the peptide was stable up to 100°C and in the pH range 6–13, and unaffected by 10mM Zn²⁺ and 10mM Mg²⁺. Cordymin inhibited HIV-1 reverse transcriptase with an IC₅₀ of 55μM. Cordymin displayed antiproliferative activity toward breast cancer cells (MCF-7) but there was no effect on colon cancer cells (HT-29). There was no mitogenic activity toward mouse spleen cells and no nitric oxide inducing activity toward mouse macrophages when tested up to 1mM.

Keywords: Antifungal, Isolation, Cordyceps