Amide–π interactions in active centres of superoxide dismutase

Abstract

In this work, the influence of amide–π interactions on stability and properties of superoxide dismutase (SOD) active centres was analysed. In the data set of 43 proteins, 5017 amide–π interactions were observed, and every active centre formed averagely about 117 interactions. Most of the interactions belonged to the backbone of proteins. The analysis of the geometry of the amide–π interactions revealed two preferred structures, parallel-displaced and T-shaped structure. The aim of this study was to investigate the energy contribution resulting the from amide–π interactions, which were in the lower range of strong hydrogen bonds. The conservation patterns in the present study indicate that more than half of the residues involved in these interactions are evolutionarily conserved. The stabilization centres for these proteins showed that all residues involved in amide–π interactions were of use in locating one or more of such centres. The results presented in this work can be very useful for the understanding of contribution of amide–π interaction to the stability of SOD active centres.