A positively charged cluster in the epidermal growth factor-like domain of Factor VII-activating protease (FSAP) is essential for polyanion binding.

ABSTRACT: FSAP (Factor VII-activating protease) is a novel plasma-derived serine protease that regulates haemostasis as well as vascular cell proliferation. FSAP undergoes autoactivation in the presence of polyanionic macromolecules such as heparin and RNA. Competition experiments suggest that RNA and heparin bind to the same or overlapping interaction sites. A proteolysis approach, where FSAP was hydrolysed into smaller fragments, was used to identify the polyanion-binding site. The EGF (epidermal growth factor)-like domains EGF2 and EGF3 of FSAP are the major interaction domains for RNA. The amino acids Arg170, Arg171, Ser172 and Lys173 within the EGF3 domain were essential for this binding. This is also the region with the highest positive net charge in the protein and is most probably located in

SUBMITTER: Altincicek B 

PROVIDER: S-EPMC1383718 | biostudies-literature | 2006 Mar

REPOSITORIES: biostudies-literature