Confinement in crystal lattice alters entire photocycle pathway of the Photoactive Yellow Protein

Abstract

Protein structural dynamics can be studied by time-resolved crystallography (TRC) and ultrafast transient spectroscopic methods. Here, the authors perform electronic and vibrational transient absorption measurements to characterise the full photocycle of Photoactive Yellow Protein (PYP) both in the crystalline and solution state and find that the photocycle kinetics and structural intermediates of PYP deviate in the crystalline state, which must be taken into consideration when planning TRC experiments.