Xanthophylls are a class of oxygen-containing carotenoids, which play a fundamental role in light-harvesting pigment−protein complexes and in many photoresponsive proteins. The complexity of the manifold of the electronic states and the large sensitivity to the environment still prevent a clear and coherent interpretation of their photophysics andphotochemistry.
Multiscale models combining quantum mechanical and classical descriptions are a very popular strategy to simulate properties and processes of complex systems. Many alternative formulations have been developed, and they are now available in all of the most widely used quantum chemistry packages. Their application to the study of light-driven processes, however, is more recent, and some methodological and numerical problems have yet to be solved.
Leggi tutto: New review on Annual Review of Physical Chemistry
We present an extension of the polarizable quantum mechanical (QM)/AMOEBA approach to enhanced sampling techniques. This is achieved by connecting the enhanced sampling PLUMED library to the machinery based on the interface of Gaussian and Tinker to perform QM/AMOEBA molecular dynamics. As an application, we study the excited state intramolecular proton transfer of 3-hydroxyflavone in two solvents: methanol and methylcyclohexane.
Leggi tutto: New article on the Journal of Physical Chemistry
Studies in cell biology often depend on imaging techniques with high spatial and temporal resolution. To this end, many artificial fluorescent protein were developed and are widely employed as molecular reporters. We analyzed two synthetic flavin-based fluorescent proteins, derived from natural light, oxygen, and voltage (LOV) sensing domain, which were engineered to obtain improved fluorescence properties.
Leggi tutto: New Article on The Journal of Physical Chemistry
Activation in photoresponsive proteins occurs in different steps: a first “ultrafast” photochemical reactions triggers a cascade of conformational changes, which lead to an active form of the protein.
Leggi tutto: Activation mechanism of Orange Carotenoid Protein now published in JACS
Accurately simulating optical spectra for multichromophoric systems is fundamental to assess the validity of quantum chemical calculations. However, it is a complicated challenge, owing to the interplay of electronic and vibronic couplings.
Leggi tutto: New article on The Journal of Physical Chemistry B
