Figure 4.

Clusterin purified from NHS with polyclonal and monoclonal antibodies contained low levels of C7. (A) Clusterin purified from NHS-MUI with anti-clusterin pAb, PC, was separated by SDS-PAGE under non-reducing conditions and the immunoblot was probed with the anti-clusterin mAb, MC. The clusterin band on the left was from the 1^st eluate acquired from the antibody-coupled column, while the band on the right was from a 2^nd, consecutive elution step. (B) Coomassie staining of clusterin purified from NHS-MUI with the anti-clusterin pAb, PC, and separated by SDS-PAGE gel under non-reducing conditions. (C) Protein composition of the 75 kDa band visualized in (A) was analyzed by mass spectrometry and protein abundance was quantified. (D) Protein compostion of the 75 kDa band (not shown) from C7 purified with the anti-clusterin mAb, MC-2D5, was analyzed by mass spectrometry and protein abundance was quantified. Results from purified clusterin in (B, C) were acquiered from the 1^st eluate. Western blot and coomassie staining are representative of at least three independent experiments. Images were taken using the ImageQuant™ LAS 400 camera system.