Cleaves peptide substrates on the N-terminus of arginine residues in dibasic pairs. Hydrolysis of polypeptides, preferably at -Xaa-|-Arg-Lys-, and less commonly at -Arg-|-Arg-Xaa-, in which Xaa is not Arg or Lys. Binds 1 zinc ion per subunit. Testis, and in a lower level in brain, heart and adrenal glands. Belongs to the peptidase M16 family.