Hexa-D-arginine is an inhibitor of the proprotein convertase furin (Ki = 100 nM).1 It also inhibits West Nile virus nonstructural protein 3 (NS3) protease (Ki = 478 nM). Hexa-D-arginine (1 µg/ml) reduces the proliferation, invasion, and migration of SW 1990 and PaTu 8988 pancreatic cancer cells, as well as decreases the levels of N-cadherin and vimentin and increases E-cadherin levels, markers of the epithelial-to-mesenchymal transition (EMT), in the same cells.2 It improves survival in a rat model of anthrax toxemia induced by the anthrax toxins protective antigen and lethal factor.3
1.Shiryaev, S.A., Ratnikov, B.I., Chekanov, A.V., et al.Cleavage targets and the D-arginine-based inhibitors of the West Nile virus NS3 processing proteinaseBiochem. J.393(Pt 2)503-511(2006) 2.Zhou, M., Zhang, Y., Wei, H., et al.Furin inhibitor D6R suppresses epithelial?mesenchymal transition in SW1990 and PaTu8988 cells via the Hippo?YAP signaling pathwayOncol. Lett.15(3)3192-3196(2018) 3.Sarac, M.S., Peinado, J.R., Leppla, S.H., et al.Protection against anthrax toxemia by hexa-D-arginine in vitro and in vivoInfect. Immun.72(1)605-605(2004)