Figure 3

Proteasomal activity in murine lung after proteasomal inhibition. The proteasomes were immunoprecipitated from Cftr^-/-- and Cftr^+/+- mice lungs (n = 3), treated with PLGA-PEG^PS341 (10 μg, intranasal), and 200 μM Suc-LLVY-AMC was used as a substrate to quantify the proteasomal activity in a 96-well plate, in triplicate. Fluorescence intensities were measured at 360 nm excitation and 440 nm emission by SpectraMax Pro fluorescence plate reader. Recombinant purified proteasome was used as a positive control while no IP served as a negative control. The data shows that PLGA-PEG mediated PS341 delivery significantly inhibits the proteasomal activity (~2 fold, p < 0.01). The data verifies the efficacy of PLGA-PEG mediated PS-341 delivery to murine lungs.