Spectroscopic properties of the carotenoid 3'-hydroxyechinenone in the orange carotenoid protein from the cyanobacterium arthrospira maxima

The characterization of the excited state dynamics of 3'-hydroxyechinenone (hECN) both in solution and bound to the orange carotenoid binding protein (OCP) in order to disclose the effects of hECN -protein interaction on excited states properties of the hECN is reported. The binding-induced conformational change and activation of the intramolecular charge-transfer state that leads to a shortening of hECN lifetime effectively makes the protein-bound hECN a more effective energy dissipator.