On the importance of π-π interactions in the structural stability of phycocyanins

The influences of ?-? interactions in phycocyanin proteins and their environmental preferences were analyzed. observations indicate that the majority aromatic residues are involved interactions. Phenylalanine (Phe) tyrosine (Tyr) found to be ??? much more frequently than tryptophan (Trp) or histidine (His). Similarly, Phe-Phe Tyr-Tyr interacting pair had highest frequency occurrence. In addition interactions, also form ?-networks phycocyanins. most favourable at distance range 5.5?7 ?, with a clear preference for T-shaped ring arrangements. Using ab initio calculations, we observed possess energy from 0 -10kJ mol-1. Stabilization centres these showed all important locating one such centres. evolutionary conserved. results obtained this study will beneficial further understanding structural stability eventual development protein engineering