Penulis: Peter Comba

The editors (SP de Visser and D Kumar) have been involved in studies of enzymatic systems such as heme enzymes like the cytochromes P450, peroxidases and catalases as well as on nonheme enzyme systems. These studies are at the forefront of chemistry and focus on short-lived species in enzymes and biomimetic complexes. Thus, for instance, the active oxidant of P450 enzymes is elusive and experimental studies gave conflicting results regarding what the active oxidant was. The studies of de Visser and Kumar and co-workers established what the active species of these enzymes is and ruled out many suggested alternative oxidants. They established a two-state-reactivity scenario for heme and nonheme iron(IV)-oxo oxidants that masquerades as multiple oxidants. Further studies established reaction mechanisms for the production of (unwanted) by-products and showed how these can be prevented. Recent collaborative work of de Visser and Kumar established a general trend for substrate hydroxylation reactions by the cytochromes P450 and explained the mechanism via a valence bond curve crossing model. De Visser and Kumar have published more than 100 scientific publications in high-impact journals and as a consequence are regular speakers and scientific meetings and conferences.