Kinetic and spectroscopic characterization of the putative monooxygenase domain of human MICAL-1

► Human MICAL monooxygenase-like domain (MICAL-MO) was overproduced and purified. ► Results highlight the functional similarity with the p-hydroxybenzoate hydroxylase class. ► The NADPH-dependent actin depolymerizing activity of MICAL-MO is confirmed. ► F-actin enhances NAD(P)H oxidation by increasing both kcat and kcat/KNAD(P)H. ► The kinetics show that the effect of MICAL-MO on F-actin may be reversible.