Author/Editor     Berne, Sabina
Title     Biokemijske in citolitične lastnosti proteina iz bukovega ostrigarja Pleurotus ostreatus (Jacq. ex. Fr.) Kumm.
Type     monografija
Place     Ljubljana
Publisher     Univerza v Ljubljani, Medicinska fakulteta
Publication year     2004
Volume     str. 138
Language     slo
Abstract     Many species of ascomycetes and basidiomycetes, both poisonous and edible, contain cytolytic proteins. From edible oyster mushroom (Pleurotus ostreatus) a novel cytolytic protein, named ostreolysin, was purified as well. Its biochemical and physicochemical properties were characterized, furthermore ostreolysin's primary and partially secondary structures were revealed. We have found that this acidic 15 kDa protein with predominantly beta-structure belongs to the aegerolysin protein family, whose representative is also a well-known hemolytic protein Asp-hemolysin. Ostreolysin likewise lyses erythrocytes at nanomolar concentrations by an apparent colloid-osmotic mechanism and is cytotoxic to some normal cell lines and mammalian tumor cells. A detailed research of ostreolysin's cytolytic activity was performed on lipid vesicles, planar monolayers and bilayers, and on some cell lines. We discovered that the presence of both sphingomyelin and cholesterol, the key components of lipid rafts, is necessary for ostreolysin pore-formation. This feature makes ostreolysin unique amongst other proteins. We clearly demonstrated a specific expression of ostreolysin during the formation of primordia and fruiting body development of oyster mushroom. It is likely that lipid rafts are also involved in fungal fruiting, since they are known to participate in cell signaling and differentiation, where lysophospholipids play an important role as well. Lysophospholipids proved to be potent inhibitors of ostreolysin's cytolytic activity. For this reason, it is tempting to speculate that they modulate ostreolysin's activity and thus regulate another ostreolysin's function that still needs to be unraveled.
Descriptors     BASIDIOMYCETES