Cholesterol and membrane phospholipid compositions modulate the leakage capacity of the swaposin domain from a potato aspartic protease (StAsp-PSI)

Establishing the Yeast Kluyveromyces lactis as an Expression Host for Production of the Saposin-Like Domain of the Aspartic Protease Cirsin

“…In addition, a robust purification protocol could be established for cirsin PSI in either glycosylated or nonglycosylated form. Our results confirm previous reports (10,24) indicating that the tendency of nonglycosylated cirsin PSI to exist in dimeric form maybe due to exposed hydrophobic surface interactions.…”

“…However, several possible roles have been associated with these domains, including as a vacuolar sorting signal and/or as an antipathogen (2,(7)(8)(9). Most of the current knowledge on PSIs, like their membrane interaction properties, structural organization, and antimicrobial activity, was acquired in studies with PSI domains from phytepsin, cardosin A, and StAP (8)(9)(10)24). However, the large number of PSI sequences available and the variety within these sequences clearly suggest that full characterization of all these plant domains has only started.…”

Evaluation of in vitro cytotoxic activity of mono-PEGylated StAP3 (Solanum tuberosum aspartic protease 3) forms

“…As for the case of antimicrobial peptides unable to lyse red blood cells [76], the presence of cholesterol into the LUVs membranes strongly diminishes the capacity of St Asp-PSI to produce leakage at all concentration assayed [29]. The presence of cholesterol in the membranes causes a reduction in the density of hydrophilic head groups at the interfacial region of the bilayer and an increase in the packaging of the phospholipid tails in the middle of the bilayer [77].…”

“…Our results show that potato aspartic proteases ( St APs) and their swaposin domain ( St Asp-PSI) are proteins with cytotoxic activity which involves plasma membrane destabilization. The ability of these proteins to produce cell death varies with the cellular type [28], [29], [30]. We have demonstrated that the lack of hemolytic and cytotoxic activities on human lymphocytes of St Asp-PSI/ St APs is attributed to the presence of cholesterol in these cell membrane types [29], [31].…”

“…The ability of these proteins to produce cell death varies with the cellular type [28], [29], [30]. We have demonstrated that the lack of hemolytic and cytotoxic activities on human lymphocytes of St Asp-PSI/ St APs is attributed to the presence of cholesterol in these cell membrane types [29], [31]. These results open a new perspective to test these proteins as possible candidates to develop new drugs that would be active against microbes but not against mammalian cells and considerer these proteins as conceptually promising agent in infectious diseases and cancer therapy.…”