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.
A hemolytic peptide from the mycophilic fungus Sepedonium chrysospermum (Bull.) Fr.
COSULICH, MARIA ELISABETTA;
2012-01-01
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 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.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
