Platelet Arp2/3 complex level.
(A) Increasing numbers of human platelets were compared to known amounts of purified Arp2/3 complex by SDS-PAGE and probed with a rabbit polyclonal antibody directed against the p34-Arc subunit of Arp2/3 complex. The graph plots the density of the detected bands against the platelet counts and the amount of purified Arp2/3 complex (inset) obtained from a single immunoblot. The amount of Arp2/3 complex divided by the platelet count was determined as the ratio between first-order equation slopes best fitting the data. Human platelets contain 14.3 × 10−21 mol Arp2/3 complex. (B) Lysates corresponding to 7 × 106 platelets (■) were compared by anti-Arp3 immunoblot to their Arp2/3 complex-depleted counterparts complemented or not with 0.5 and 1 × 10−13 mol purified Arp2/3 complex (░). The amount of Arp2/3 complex was quantified by densitometric analysis of the immunoblots. The histogram plots the percentage ± SD of the density relative to total from 3 independent assays.
