Seminars at the Franklin: Professor Steve Meech

1st August 2024, 10:30 – 11:30 am


The Diverse Photophysics of Fluorescent Proteins


Fluorescent proteins (FPs) have been a revolutionary force in bioimaging. The discovery of the green fluorescent protein (GFP) dramatically enhanced our ability to image specific proteins in living systems in real time. GFP was quickly shown to have an array of stable mutants yielding emission tuneable across the visible spectrum, allowing the study of protein-protein interactions for example. The FPs were variously shown to undergo excited state proton transfer, excited state isomerization and permanent photochromic reactions. The latter two led to the practical application of super resolution bioimaging and the development of optical highlighter imaging respectively. All of these properties ultimately derive from the extraordinary diverse photophysics of the chromophore of GFP, HBDI.

In this presentation, the photophysics of HBDI will be reviewed, along with some of the methods of ultrafast spectroscopy employed in its study. We then describe how the protein matrix controls HBDI photophysics, leading to the diversity in FP behaviour. These measurements not only allow better understanding of – and control over – FP behaviour but also affords the opportunity to investigate protein structural relaxation dynamics away from equilibrium.


Prof. Steve Meech is a Professor of Physical Chemistry at the University of East Anglia. His research is focused on understanding ultrafast dynamics of complex condensed phase systems including liquid state dynamics, fast photochemical reactions and photoactive proteins. He maintains a number of national and international research collaborations which facilitates the application of ultrafast methods to some of the most interesting and challenging problems.