The binding of filipin with cholesterol in sealed and unsealed ghosts prepared from human erythrocytes and in right-side-out and inside-out vesicles prepared from ghosts follows second order kinetics (first order in each reactant). The second order rate constant of interaction of filipin with cholesterol, determined by stopped flow measurements of the initial rate, is slower in sealed ghosts th...

The polarization of sterol-enriched lipid microdomains has been linked to morphogenesis and cell movement in diverse cell types. Recent biochemical evidence has confirmed the presence of lipid microdomains in plant cells; however, direct evidence for a functional link between these microdomains and plant cell growth is still lacking. Here, we reported the involvement of lipid microdomains in NA...

The data show that the filipin complex in water has a characteristic fluorescence spectrum with a broad emission maxima at 497nm. Addition of cholesterol to the aqueous solution decreases the absorbance, the corrected fluorescence, and the partial quantum efficiency. The reduction in partial quantum efficiency, which is independent of the concentration of filipin, is definitive evidence that th...

PURPOSE To determine the effects of contact lenses (CLs) and Pseudomonas aeruginosa (PA) infection on localization of cystic fibrosis transmembrane conductance regulator (CFTR) on corneal surface epithelial cells and the association between lipid raft formation and CFTR in mediating PA binding and internalization in ocular surface epithelium. METHODS CFTR immunolocalization was evaluated in v...

Mammalian sperm cells are activated prior to fertilization by high bicarbonate levels, which facilitate lipoprotein-mediated cholesterol efflux. The role of bicarbonate and cholesterol acceptors on the cholesterol organization in the sperm plasma membrane was tested. Bicarbonate induced an albumin-independent change in lipid architecture that was detectable by an increase in merocyanine stainin...

Purpose of review Niemann-Pick disease type C (NP-C) is a neurovisceral disorder that may be more prevalent than earlier estimates. Diagnosis of NP-C is often delayed; a key aim for clinical practice is to reduce this delay. Recently, substantial progress has been made in the field of NP-C screening and diagnosis, justifying an update to the existing recommendations for clinical practice. Rec...

Caveolae represent an important structural element involved in endothelial signal-transduction. The present study was designed to investigate the role of caveolae in endothelium-dependent relaxation of different vascular beds. Caveolae were disrupted by cholesterol depletion with filipin (4x10(-6) g L(-1)) or methyl-beta-cyclodextrin (MCD; 1x10(-3) mol L(-1)) and the effect on endothelium-depen...

Structural sterols are abundant in the plasma membrane of root apex cells in Arabidopsis thaliana. They specifically accumulate in trichoblasts during the prebulging and bulge stages and show a polar accumulation in the tip during root hair elongation but are distributed evenly in mature root hairs. Thus, structural sterols may serve as a marker for root hair initiation and growth. In addition,...

We investigated the distribution of sterols in the cell membrane of microvascular endothelium (mouse pancreas, diaphragm, brain, heart, lung, kidney, thyroid, adrenal, and liver) with the polyene antibiotic filipin, which reportedly has binding specificity for free 3-beta-hydroxysterols. In some experiments, concomitantly, cell-surface anionic sites were detected with cationized ferritin. Vesse...

A narrow zone of plasma membrane between the head and body of a protozoan from termites undergoes continual in-plane shear because the head rotates continuously in the same direction relative to the cell body (Tamm, S.L., and S. Tamm, 1974, Proc. Natl. Acad. Sci. USA 71:4589-4593). Using filipin and digitonin as cytochemical probes for cholesterol and related 3-beta-hydroxysterols, we found a h...