ABSTRACT
The hemolytic activity of an extract of the mycoparasite Sepedonium chrysospermum (teleomorph Hypomyces chrysospermus) was detected and characterized. Extraction of the fungal biomass by methanol yielded a fraction in which the hemolytic activity against human red blood cells corresponded to a peptide with a molecular mass of 7,653.72 Da and an isoelectric point of approximately 5.8. The peptide was temperature resistant, and the hemolysis was only partially inhibited, even after a 30-min pre-incubation at 100°C. Its hemolytic activity was unaffected by treatment with proteolytic enzymes such as trypsin. Among the divalent cations assayed, Hg(2+) was the strongest inhibitor of hemolysis. The reducing agent, dithiothreitol, and the membrane lipid, cholesterol, demonstrated concentration-dependent inhibitory activities. Finally, hemolytic activity triggered by the peptide was analyzed by scanning electron microscopy, and a pore-forming activity was detected.
