Investigations on the role of cation-π interactions in active centers of superoxide dismutase

Abstract

In this study, we have analysed the influence of cation–π interactions on stability and properties of superoxide dismutase (SOD) active centres. The number of interactions formed by arginine is higher than by lysine in the cationic group, while those formed by histidine are comparatively higher in the π group. The energy contribution resulting from most frequent cation–π interactions was in the lower range of strong hydrogen bonds. The cation–π interactions involving transition metal ions as cation have energy more negative than –418.4 kJ mol-1. The stabilization centres for these proteins showed that all the residues involved in cation–π interactions were important in locating one or more of such centres. The majority of the residues involved in cation- π interactions were evolutionarily conserved and might have a significant contribution towards the stability of SOD proteins. The results presented in this work can be very useful for understanding the contribution of cation–π interactions to the stability of SOD active centres.

Keywords

• superoxide dismutase
• cation–π interactions
• catalytic site