Lipid-facilitated opening of the ADAM10 sheddase revealed by enhanced sampling simulations

Abstract

ADAM10 is a crucial membrane-bound metalloprotease that regulates cellular physiology by cleaving and releasing membrane-anchored proteins, including adhesion molecules and growth factor precursors, thereby modulating cell signaling, adhesion, and migration. Despite its central role, its activation mechanisms are not fully understood. Here, we model how phosphatidylserine (PS) exposure during apoptosis triggers ADAM10 activation. We confirmed that PS externalization leads to shedding of CD43 from the surface of T cells via ADAM10 activity. Intriguingly, ADAM10 activation correlated with a loss of monoclonal ADAM10 antibody binding, suggesting a PS-induced conformational change that alters epitope accessibility. To explore this lipid-mediated conformational change of ADAM10, we employed molecular dynamics (MD) simulations to map the conformational landscape of ADAM10. Our simulations revealed that in the absence of PS, ADAM10 samples predominantly closed and intermediate states. By contrast, the presence of PS destabilizes the closed conformation, thereby favoring open states. We provide a mechanistic explanation for this PS-induced conformational change which drives ADAM10 activation and loss of mAb binding through conformational change. These findings offer new insights into the lipid-mediated regulation of ADAM10 and its conformational dynamics.