We investigated the effects of inhibitors of clathrin-mediated endocytosis (chlorpromazine and K(+) depletion) and of caveolae-mediated uptake (filipin and genistein) on internalization of FITC-poly-l-lysine-labeled DOTAP/DNA lipoplexes and PEI/DNA polyplexes by A549 pneumocytes and HeLa cells and on the transfection efficiencies of these complexes with the luciferase gene. Uptake of the comple...

Cells of the yeast sterol auxotroph GL7 were grown on either ergosterol or cholesterol to mid-logarithmic phase and total membrane fractions prepared. Activities of phospholipid biosynthetic enzymes in the two cell types were determined. The rates of phosphatidyl-ethanolamine-phosphatidyl-choline-N-methyl transferase and acyl-CoA-alpha-glycerol-3-phosphate transcylase were significantly greater...

The polyene antibiotic, filipin, binds to 3 beta-hydroxysterols. The initial rate of filipin-sterol association, monitored in a stopped-flow spectrophotometer, was first order in each reacting partner. The ratio of rate constants in intact mycoplasma cells relative to isolated, unsealed membranes provides an estimate of sterol distribution in the membrane bilayer. Cholesterol is distributed sym...

Red light given to dark-grown etiolated leaves of Hordeum vulgare L. in vivo or to crude homogenates increases the phytochrome content of the 20,000 g pellet on centrifugation. The steroids cholesterol and stigmasterol inhibit this red light-induced phytochrome pelletability. Filipin (a polyene antibiotic, which is known to combine with steroids) inhibits red light-induced phytochrome pelletabi...

introduction: the novel development of the (hba) sperm- hyaluronan binding assay has now been routinely used in some laboratories worldwide to predict sperm maturity and functionality. the purpose of this study was to evaluate the correlation between hba score and histone deficiency, protamine content and dna fragmentation. methods: during april- march 2012 patients who were enrolled at shiraz-...

Sterols are considered structural components of higher plant membranes on the basis of their presence in membrane-containing subcellular fractions [1—3], their effect on plant membrane permeability when added exogenously [4,5] and the sensitivity of plant cells to the polyene antibiotic filipin [6—8], which action is known to depend on the presence of sterols in the membrane (see [8]). Our rece...