Selective recognition of cholesterol by GST-PFO. (A) Protein-lipid overlay assay. Indicated amounts of lipids were spotted on nitrocellulose membrane and incubated with 1 μg/ml GST-PFO. Immunoreactive spots were revealed by chemiluminescence. (B) 6-Carboxyfluorescein release from liposomes of indicated composition induced by 15 μg/ml GST-PFO. The data are expressed as percentage of the total amount of 6-carboxyfluorescein released from liposomes by 0.2% Triton X-100. (C) SPR sensograms of binding of 10 μg/ml GST-PFO or 20 μg/ml GST to liposomes of indicated lipid composition immobilized on the surface of sensor chip L1. Binding of GST-PFO to liposomes was carried out for 600 s after which the samples were washed for another 600 s. In (A) and (C) data represent one of three independent experiments; in (B) mean ± SEM from three experiments is shown. Chol – cholesterol; Cer – ceramide; SM – sphingomyelin.