... 133–138 at the exposed part of the cathepsin B molecule near the occluding loop(Fig. 2C). The location of the epitope indicates that the binding of 2A2 mAb might change the conforma-tion of the loop, ... of 161.8, 28.2 and 13.2 kDa, respectively. The formation of the cathepsin B ⁄ cystatin C complexwas seen as a shift of the elution peak of cathepsin B(Fig. 6A). The addition of 2A2 mAb to the ... which the N-terminus of the inhibitor first binds to the enzyme, displacing the occluding loop, followed by the binding of another two loops of the inhibitor [24].Besides protein inhibitors, the...