[Efficiency of non-Photochemical Fluorescence Quenching of Phycobilisomes by the Orange Carotenoid Protein].

We report on theoretical efficiency of non-photochemical fluorescense quenching of phycobilisomes by the orange carotenoid protein. The created 3D computer model of the three-cylindrical phycobilisomes core allowed us to determine the distances between centers of mass of all phycobilin chromophores of the core and calculate the time and an average number of energy migration steps for the resulting non-radiative excitation transfer from the phycobilisomes to photosystem II. The obtained kinetic scheme equations for a way of energy transfer confirm the incomplete interception of energy flow in the phycobilisomes core by the orange carotenoid protein. Theoretical estimation of the rate of phycobilisomes quenching is in good agreement with experimental data.