Figure 3: Allosteric inhibition of APN catalysis by CoV S proteins.
From: Allosteric inhibition of aminopeptidase N functions related to tumor growth and virus infection
APN catalysis was monitored as optical density (OD) with soluble hAPN and pAPN ectodomains (see Methods). (a) Activity determined with pAPN and hAPN (0.04 μM) alone or with porcine CoV S proteins untreated (S1H, S3H) or endoglycosidase H-treated (S1Heh, S3Heh), or with the TGEV RBD fragment; all these proteins bind specifically to pAPN16,35. The unrelated PVR-Fc protein was used as control. Sample without APN (−). (b) Activity determined at 60 min with increasing RBD:APN molar ratios. (c) Inhibition of pAPN catalytic activity by the TGEV RBD over time. Inhibition was computed according to the OD in b.
