Figure 4.

Enzymatic properties of purified Aca s 4. (a) pH profile determined with RBB-starch as a substrate. Mean values ± SE are normalized to the maximum value. (b) Activation effect of NaCl on amylolytic activity of Aca s 4 (solid line) and porcine pancreatic α-amylase (PPA) (dashed line) measured with the RBB-starch assay. Mean values ± SE are expressed as a percentage of activity relative to the control without NaCl (100%). (c) Inhibition profile of Aca s 4 determined by a library of PAMIs with the general structure Ac-XHWYYRCW-NH₂; the X position contains one of the 20 naturally occurring amino acids as indicated. The inhibition sensitivity of the purified Aca s 4 (hatched) is compared to that of whole body extracts of A. siro (gray) and D. farinae (black). Mean values ± SE are expressed as the percentage of amylolytic activity (RBB-starch assay) relative to the uninhibited control (100%).