Figure 4.
Screens with labeled substrates do not reflect activity in the fluorescamine assay. Normalized activity of endpoint assays (Table I) does not correlate with (A) a screen of all possible −2 and −1 sequences using fluorophore‐labeled peptides (r 2 = 0.18)31 or (B) a screen of all possible +1 and +2 sequences using surface‐attached peptides (r 2 = 0.02).30 Lines represent a hypothetical perfect correlation; deviation from the line indicates disagreement between observed and predicted results. Error bars come from experimental results (x‐axis) or are extrapolated based on the reported precision of values used for predictions (y‐axis).