SSM3 tetraTFA is against furin cleavage of the Pyr-RTKR-AMC substrate with an EC
50
of 54 nM in vitro cleavage assays and cell-based tests.SSM3 tetraTFA (0.1-25 μM) inhibits the furin-dependent conversion of PA83 into PA63 in a dose dependent manner, it inhibits PA83 processing in the cleavage reactions.SSM3 tetraTFA shows comparable potency against furin (K
i
=0.012 μM) and PC6B (K
i
=0.004 μM), these compounds preferentially inhibited furin over PACE4 (K
i
=0.041 μM) by 2- to 10-fold and over PC7 (K
i
=0.595 μM) by 11- to 76-fold. In addition, it inhibits LF (K
i
=1.241 μM) 25- to 167-fold less effectively than in furin and shows no measurable inhibition against trypsin and MT1-MMP.
