Interactions outside the proteinase-binding loop contribute significantly to the inhibition of activated coagulation factor XII by its canonical inhibitor from corn.

ABSTRACT: Activated factor XII (FXIIa) is selectively inhibited by corn Hageman factor inhibitor (CHFI) among other plasma proteases. CHFI is considered a canonical serine protease inhibitor that interacts with FXIIa through its protease-binding loop. Here we examined whether the protease-binding loop alone is sufficient for the selective inhibition of serine proteases or whether other regions of a canonical inhibitor are involved. Six CHFI mutants lacking different N- and C-terminal portions were generated. CHFI-234, which lacks the first and fifth disulfide bonds and 11 and 19 amino acid residues at the N and C termini, respectively, exhibited no significant changes in FXIIa inhibition (Ki = 3.2 ± 0.4 nm). CHFI-123, which lacks 34 amino acid residues at the C terminus and the fourth and fifth disu

SUBMITTER: Korneeva VA 

PROVIDER: S-EPMC4022879 | biostudies-literature | 2014 May

REPOSITORIES: biostudies-literature