Analogs of LDL Receptor Ligand Motifs in Dengue Envelope and Capsid Proteins as Potential Codes for Cell Entry

Figure 1

Influence of LDL on uptake of E⁰¹³¹-FITC by HeLa cells. An assay solution of 5 µM E⁰¹³¹-FITC in PBS containing 5 mM MgCl₂ was added to HeLa cells after cultures were preconditioned overnight in medium with 3% FBS and 1 µM mevastatin and rinsed with PBS-MgCl₂. In parallel, 100 µg human LDL was added to mixture. Cells were incubated for 60 minutes. Fluorescence image (a) shows binding of E⁰¹³¹-FITC to HeLa cells. An overlay image of frame (a) on the corresponding bright-light image is shown in frame (b). Images in frames (c) and (d) are enlargements of an area in (b) and show E⁰¹³¹-FITC as clusters on the cell surface. Binding of E⁰¹³¹-FITC in the presence of unlabeled LDL is shown in frame (e) with the corresponding overlay in frame (f). Images in frames (g) and (h) are enlargements of a region in frame (f) and show that fluorescence is present in the cytoplasm.

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