FIG. 7. Thiol isomerases do not activate b3. Washed
human platelets were incubated with recombinant human
PDI (1 or 10 lM), ERp5 (1 or 10 lM), and ERp57 (1 or
10 lM), either individually or in combination, in Hepes
Tyrode buffer containing 5 lM reduced glutathione (GSH),
1 lM oxidized glutathione (GSSG), and 1 mM CaCl2 for
10 min at 37C. Samples were then probed for activation of
b3 integrin using conformation-specific antibody PAC-1
(FITC-labeled) using flow cytometry. (A) Histograms
showing mean fluorescence intensity for 10 lM PDI (green)
and combination of PDI, ERp5, ERp57 ( purple) each at
10 lM compared to resting platelets (blue) and platelets
stimulated with 1 U/ml a-thrombin (red). (B) Mean fluorescence
intensity of PAC-1 staining for various experimental
conditions compared to resting platelets and platelets
stimulated with 1 U/ml a-thrombin. Bars represent mean –
SD for three separate experiments. To see this illustration in
color, the reader is referred to the web version of this article
at www.liebertpub.com/ars