Figure 3.

Hex and Gal are localized on external leaflet microdomains of the plasma membrane. Jurkat cells were treated with EZ-Link Sulfo-NHS-LC-Biotin to label cell surface proteins. After lipid microdomain purification, the biotinylated proteins contained in light-density fraction 3 were purified by avidin affinity chromatography. (A) Aliquots of concentrated and solubilized fraction 3 lipid microdomains (LM3), flow-through (F), and eluate (E) were analyzed by Dot blotting using HRP-conjugated streptavidin (Strep-HRP). (B) Total Hex, Hex A, and Gal enzymatic activities found in LM3, F, and E for resting (-) and PHA-stimulated (+) cells were expressed as total mU (tot. mU). The mean ± SEM of three independent experiments is reported. *** p < 0.001 (PHA-stimulated vs. resting cells).