Capturing biomolecular interactions and assembly with a molecular photonic scale

 

Professor Philipp Kukura

Department of Chemistry, Physical and Theoretical Chemistry Laboratory

University of Oxford, UK

 

The cellular processes underpinning life are orchestrated by proteins and the interactions they make with themselves and other biomolecules. A range of techniques has been developed to characterise these associations, operating from the ensemble all the way to the single molecule level. Structural and dynamic heterogeneity, however, continues to pose a fundamental challenge to existing analytical and structural methodologies, despite being key to protein and drug function. This could in principle be addressed by approaches capable of detecting, identifying and quantifying individual molecular assemblies in solution. I will present recent developments demonstrating that interferometric scattering mass spectrometry (iSCAMS) can mass-image single biomolecules in solution with simultaneous nanometre precision and mass accuracy comparable to native mass spectrometry in the gas phase. As a result, we can resolve oligomeric distributions at high dynamic range, detect small-molecule binding, and quantitatively mass-image not only biomolecules composed of amino acids, but also heterogeneous species such as glyco- and lipoproteins. These capabilities enable us to determine the equilibrium constants and thereby the molecular mechanisms of homo- and hetero-oligomeric protein assembly, which I will illustrate with heat-shock protein oligomerisation and drug-induced HIV glycoprotein cross-linking. Furthermore, by virtue of the intrinsic nanometre spatial precision, we can mass-monitor the dynamics of mesoscopic objects, such as individual amyloidogenic protein aggregates and actin filaments down to the single molecule level. Coupled with clear routes towards future improvements in mass resolution and precision well below the kDa range and extension towards membrane proteins, these results illustrate how single molecule mass imaging provides universally-applicable and spatially-resolved access to the mechanisms and dynamics of protein assemblies, their interactions and how they form nano- and mesoscopic structures, one molecule at a time.

 

 

 

Keynote Speaker (Biography)

 

Prof. Philipp Kukura received his PhD degree in 2006 from University of California at Berkeley and then worked as a postdoctoral fellow at ETH Zurich with Prof. Vahid Sandoghdar (2006-2010). He then joined St Hugh’s College, Oxford as an EPSRC Career Acceleration Fellow (2010-2015) and University Lecturer (2011-2013) at the University of Oxford. He was promoted to Associate Professor in 2014 and Professor in 2016.

 

Prof. Kukura develops and applies novel spectroscopic and microscopic imaging techniques with the aim of visualizing and thereby studying biomolecular structure and dynamics. Of particular importance are Prof. Kukura’s recent breakthroughs in scattering-based optical microscopy, where his group was first to demonstrate nanometre-precise tracking of small scattering labels with sub-ms temporal resolution, which enables highly accurate measurements and mechanistic insight into the structural dynamics of biomolecules such as molecular motors and DNA, and thereby their function and interactions. Secondly, his group was able to develop ultrasensitive label-free imaging and sensing in solution, down to the single molecule level, which has the potential to revolutionise our ability to study molecular interactions and self-assembly.

 

Prof. Kukura was an elected Fellow of the Royal Society of Chemistry in 2011 and has received many prestigious awards, including

2018 UK Blavatnik Award for Young Scientists Finalist

2018 Royal Society Wolfson Research Merit Award

2017 EBSA Young Investigator Award and Medal

2015 Royal Society of Chemistry Marlow Award

2015 Visiting Professor Sapienze University of Rome

2014 ERC Starting Investigator Award

2014 Visiting Professor University of Erlangen

2011 Royal Society of Chemistry Harrison-Meldola Award