Furin

Furin (proprotein convertase subtilisin/kexin type 3, PCSK3, PACE) belongs to the proprotein convertases involved in the proteolytic maturation of many proteins in the secretory pathway. In addition to cellular substrates, furin activates the proteins of many bacterial and viral pathogens, including the Spike-protein of the severe acute respiratory virus 2 (SARS-CoV-2). Recombinant human furin is expressed in the human HEK293S cell line facilitating homogenous glycosylation. Active furin is selectively purified using inhibitor based affinity purification. The protein is suited for enzymatic assays, activation of furin's substrate proteins and protein crystallography. Ca2+ is crucial for activity; avoid calcium chelators like citrate, EDTA or EGTA in buffers. For dilution below 0.1 mg/ml include detergents (e.g. 0.2% Triton-X-100) in buffers. The activity is defined by the amount of furin (µg) that releases 1 pmol AMC from Pyr-Arg-Thr-Lys-Arg-AMC in 1 minute (in 100 mM Hepes/NaOH pH 7.0, 2 mM, 0.2% Triton-X-100 at 37°C with 200 µM Pyr-Arg-Thr-Lys-Arg-AMC).