Figure 6.

Immunodetection of VASP in mouse brain extracts and of Evl in platelet extracts. (a) Platelet extract (1, 2, and 4 μl, corresponding to 0.7, 1.4, and 2.1 pmol of VASP, in lanes 1, 2, and 3, respectively), Mena (−/−) mouse brain extracts (10 and 20 μl in lanes 4 and 5), and wild-type mouse brain extracts (10 and 20 μl in lanes 6 and 7) were analyzed by immunoblotting using polyclonal M4 anti-VASP antibody. Assuming that the limit of detection is 0.4 pmol, the data indicate that the maximum concentration of VASP in brain extracts is 20 nM, a concentration too low to support Listeria movement. (b) Wild-type mouse brain extracts (5, 10, and 20 μl corresponding to 3.5, 7, and 14 pmol of Evl in lanes 1, 2, and 3, respectively) and 10, 20, and 40 μl platelet extracts (lanes 4, 5, and 6, respectively) were analyzed by immunoblotting using a polyclonal anti-Evl antibody. Assuming that the lower limit of detection is 2 pmol Evl, the data indicate that the maximum concentration of Evl in platelets is 50 nM, which is too low to support motility of Listeria.