Fig 3.
Effect of PS-exposure on cell death induced by 5 μM of peptides R-DIM-P-LF11-322 (left) or DIM-LF11-318 (right) in the presence of normal (100%) levels of PS exposed by melanoma cell line A375 (no PSD) or in the presence of reduced levels of PS (1xPSD, 2xPSD and 5xPSD (1xPSD 2,7 μg/105 cells) (at least 3 experiments). 5xPSD (13,4 μg/105 cells) leads to an approximate reduction of PS-exposure in the outer leaflet (OL) of the plasma membrane of A375 by 40% (at least 2 experiments). R-DIM-P-LF11-322 in contrast to DIM-LF11-318 shows a significant reduction in killing of melanoma cells in the presence of reduced PS-exposure. PS-exposures was determined by binding to Annexin V-Alexa Fluor 488 (λex = 488 nm and λem = 530 nm). For the measurements serum free media was used to prevent proteolysis of PSD during 30 min of incubation. PSD, PS-decarboxylase PkPSD.