Model for surface-dependent factor XII activation: the roles of factor XII heavy chain domains.

ABSTRACT: Factor XII (FXII) is the zymogen of a plasma protease (FXIIa) that contributes to bradykinin generation by converting prekallikrein to the protease plasma kallikrein (PKa). FXII conversion to FXIIa by autocatalysis or PKa-mediated cleavage is enhanced when the protein binds to negatively charged surfaces such as polymeric orthophosphate. FXII is composed of noncatalytic (heavy chain) and catalytic (light chain) regions. The heavy chain promotes FXII surface-binding and surface-dependent activation but restricts activation when FXII is not surface bound. From the N terminus, the heavy chain contains fibronectin type 2 (FN2), epidermal growth factor-1 (EGF1), fibronectin type 1 (FN1), EGF2, and kringle (KNG) domains and a proline-rich region. It shares this organization with its homolog, pro

SUBMITTER: Shamanaev A 

PROVIDER: S-EPMC9131904 | biostudies-literature | 2022 May

REPOSITORIES: biostudies-literature