Joseph Nabarro

Probing the dynamics, orientation and conformation of lipopolysaccharide in bacterial membranes through bio-orthogonal chemistry and single-molecule biophysics

About me

I completed a Natural Sciences Integrated Masters degree at the University of York as a mature student. During my studies I contributed to several research projects including probing bacteriophage portal protein assembly mechanisms via synthesis and analysis of chimeric assemblies, harnessing ion mobility mass spectrometry to characterise individual eukaryotic N-glycan isoforms and using total internal reflection fluorescence microscopy to describe the behaviour of co-stimulatory receptors in the membranes of mammalian antigen-presenting cells.
These projects, together with other experiences during my undergraduate studies, cultured an ambition to take part in research using novel integrated scientific approaches to further our understanding of key biological systems. My multifaceted PhD project enables me realise this objective, working with the expert direction of leaders in their fields, developing upon my existing interests and experiences, whilst acquiring new skills as the project proceeds.

My project

The outer membrane of Gram-negative bacteria is asymmetric. The outer leaflet is composed of lipopolysaccharide (LPS) molecules interspersed with outer membrane proteins (OMPs). In addition to being a potent virulence factor (inducing septic shock in human hosts), LPS is thought to protect bacteria against environmental / chemical challenge and contributes to antibiotic resistance.
Using an interdisciplinary approach combining bio-orthogonal click-labelling of LPS and OMPs, and single-molecule fluorescence microscopy, we aim to explore the underpinning mechanisms governing the spatio-temporal dynamics of LPS and its insertion machinery during cell growth and fission, This approach will utilise simultaneous click-labelling of LPS and OMPs after metabolic labelling with appropriate sugar and amino acid functionalised analogues followed by fluorescence co-localisation microscopy. We will also probe LPS conformation through hetero-bifunctional metabolic labelling of the oligosaccharide in LPS followed by click-labelling with appropriate dyes and single-molecule FRET experiments to determine intramolecular distances.


Not available.