Fig. 4.
CatL activity levels and expression of the DC forms of CatB and CatL are reduced in the α5β1-negative CHO cells. CatL (A) and CatB (B) activity in cell lysates was measured against small fluorogenic peptide substrates. Results shown are the averages of 3 experiments. Error bars indicate SEM. *, P ≤ 0.001 relative to CHO K1 cells. ⋀, P ≤ 0.02 relative to CHO B2 cells. (C) Untransfected CHO cells and CHO cells transfected with a plasmid encoding human CatL were analyzed by immunoblotting for CatL. (D and E) Cell lysates and supernatants from equivalent numbers of cells transfected with plasmids encoding human CatB (D) or CatL (E) were concentrated and analyzed by immunoblotting for CatB or CatL as indicated. haDC, DC form of endogenous hamster CatL; huPro, huSC, and huDC, proform, SC form, and DC form, respectively, of overexpressed human CatB and CatL.