Immunoanalysis of platelet neurogranin and clusterin.

(A-D) Gel-filtered platelets were either fixed in 3.7% formaldehyde (nonpermeabilized) or fixed with permeabilization in the presence of 0.1% Triton-X, followed by flow cytometric analysis using anticlusterin, anti-IIb/IIIa, or antineurogranin antibodies and the FITC-conjugated species-specific secondary antibody (in C, the FITC-conjugated antirabbit and antimouse controls are essentially superimposed). (E-F) Ten micrograms of solubilized HepG2 cells (hepatocyte cell line), human brain, or purified platelet lysates were analyzed by SDS-PAGE,17 and immunoblot analysis were completed by using 1:1000 dilutions of either antineurogranin (18% SDS-PAGE) or anticlusterin (8% SDS-PAGE) antibodies. The anticlusterin antibody recognized 2 platelet immunoreactive species under shorter exposure. Although the relative neurogranin and clusterin protein abundances are suboptimally quantified by these analyses, platelet clusterin appears to demonstrate considerable expression when compared with that previously identified in hepatocytes.31