Kinetic characterisation of o-aminophenols and aromatic o-diamines as suicide substrates of tyrosinase

► This study describes the importance of proton transfer from the substrates to oxy-tyrosinase. ► During the catalysis, one proton is transferred to base B2 and other to the peroxide group. ► The transfer of two protons to the peroxide group probably occurs during suicide inactivation. ► The limiting step of the catalysis could be the transfer of the first proton to the peroxide group. ► The limiting step for inactivation could be second proton transfer to the peroxide group.