This family represents a protealysin inhibitor called Emfourin, after M4 family inhibitor (M4in), as protealysin is a metallo- endopeptidase from MEROPS peptidase family M4 [1]. Emfourin is a potent inhibitor that forms a 1:1 stoichiometry complex with protealysin.

1: The protealysin operon encodes emfourin, a prototype of a novel family of protein metalloprotease inhibitors. Chukhontseva KN, Berdyshev IM, Safina DR, Karaseva MA, Bozin TN, Salnikov VV, Konarev PV, Volkov VV, Grishin AV, Kozlovskiy VI, Kostrov SV, Demidyuk IV; Int J Biol Macromol. 2021;169:583-596. PMID:33385454