The inhibitory effect of the anti-β-lactamase antibody is also manifested in Figure , depicting the initial reaction rate (V0, calculated from the visible absorbance curves) vs antibody concentrations. Specifically, while without antibody co-incubation PFK amyloid fibrils exhibited an initial reaction rate of approximately 350 µg/µL*h, addition of just 2.9 µM antibody, almost three orders of magnitude lower than the PFK concentration, reduced V0 almost by half, and higher antibody concentrations further inhibited PFK amyloid fibril catalysis (Figure ). Overall, the anti-β-lactamase antibody experiments in Figure suggest that the PFK amyloid fibrils surface may exhibit structural features that mimic β-lactamase active sites.