A hemolytic peptide from the mycophilic fungus Sepedonium chrysospermum (Bull.) Fr.

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 preincubation
at 100°C. Its hemolytic activity was unaffected by
treatment with proteolytic enzymes such as trypsin. Among the
divalent cations assayed, Hg2+ was the strongest inhibitor of
hemolysis. The reducing agent, dithiothreitol, and the
membrane lipid, cholesterol, demonstrated concentrationdependent
inhibitory activities. Finally, hemolytic activity
triggered by the peptide was analyzed by scanning electron
microscopy, and a pore-forming activity was detected.