I am expressing furin gene in a furin deficient cell line (LoVo), but I always get 2 bands on my western blot ~ 87kDa, corresponding to furin expression and a lower band, of approximately 50kDa, even on negative control cells (not transfected). I am using Santa Cruz H-220 antibody, any clue on what the lower band could be?
Lanes on the gel:
Ladder, negative control, one , two, three, four, seven and 24 hours after transfection.