Biological and Medicinal Chemistry

Modeling Structure and Absorption Spectra of the Bacteriophytochrome-Based Fluorescent Protein IFP1.4

Authors

Abstract

We report the results of quantum mechanics/molecular mechanics (QM/MM) simulations of structures and absorption spectra of the fluorescent protein IFP1.4 engineered from the chromophore-binding domain of Deinococcus radiodurans (DrCBD). In this work, we focus on different protonation states of the biliverdin chromophore in the red-absorbing form of the protein. To this goal, the protein with the all-protonated chromophore as well as the structures obtained by removal of protons from the biliverdin pyrrole rings to a suitable acceptor within the system are considered. Several quantum chemistry methods to compute the S0→S1 excitation energies are used in the QM part to estimate shifts in the absorption band maxima upon chromophore deprotonation.

Version notes

This is the first version of the manuscript

Content

Thumbnail image of IFP14ms.pdf