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Georgina Charlton

Background

BSc Hons Chemistry 2011-2014 University of Warwick

MSc AS:MIT 2015-2016 University of Warwick

PhD MAS CDT 2016-present University of Warwick

PhD Project

Life sciences project with Dr Alex Jones on "Developing mass spectrometry based proteomic methods to identify and quantify protein carbonylation in plants" sponsored by Syngenta.

Carbonylation modifications are used as key biomarkers of oxidative stress in animals and plants. However, due to their low abundance, carbonylation modifications have been difficult to analyse and most previous enrichment work has been done at the protein level, meaning most peptides analysed were not carbonylated. The abundance of carbonylation of proteins is typically measured using colourimetry after derivatisation with 2,4-Dinitrophenylhydrazine (DNPH). However, colourimetry does not reveal the identification of the protein nor the site of modification. We have explored using DNPH derivatisation as a basis for enrichment of carbonylated peptides before analysis by mass spectrometry, but with limited success probably due to the reversible nature of the hydrazone bond formed. As an alternative, we are developing an enrichment strategy at the peptide level using other tags which bind to carbonyl groups. A suitable enrichment strategy will allow analysis of complex mixtures giving us a better understanding of proteins and sites which are more susceptible to carbonylation.

I intend to do further research on the effect of drought on carbonylation and yield loss in maize. Maize is the worlds third largest food crop after wheat and rice (according to the world health organisation). Crop loss can be devastating causing loss of income for farmers and starvation to those who rely on local crops for food. I intend to isolate proteins and amino acid sites within the maize proteome which are susceptible to carbonyl modifications, allowing us to better understand the mechanism of damage caused by drought stress leading to yield loss.

Maize progression

Here's how the maize plants have progressed from planting to maturity.

Conferences Attended

The 15th East Midlands Proteomics Workshop on the 16th of November 2016 at Nottingham Trent University.

The 4th Early Career Researchers Meeting in Analytical Biosciences on the 15th and 16th of March 2017 at the University of Warwick. Poster presented.

Syngenta Product Safety & Biology Research Collaborations Review Event on the 5th of September 2017 at Jealott’s Hill. Poster presented.

Syngenta Product Safety & Biology Research Collaborations Review Event on the 6th & 7th of September 2018 at Jealott’s Hill. Talk and poster presented.

The 39th BMSS annual meeting on the 10th-13th of September 2018 at Churchill College Cambridge. Poster presented.

The 17th East Midlands Proteomics Workshop on the 24th of October 2018 at Lincoln University. Poster Presented.

Advances in the Study of Lipid and Protein Oxidation: From Methods to Targets on the 13th-15th March 2019 at the University of Ghent Belgium. Talk and poster presented.

The 67th ASMS Conference on Mass Spectrometry and Allied Topics on the 2nd-6th of June 2019 in Atlanta, Georgia, USA. Poster presented.

Outreach

During open days I have run the Proteomics stand in Life Sciences at Warwick. This involved demonstrating a simple time of flight mass spectrometer using ping-pong balls to both prospective students and their families. The families weren't necessarily from a scientific background, so the explanation had to be accessible to people at all levels, and not just those with a scientific background. The work also involved answering questions about proteomics, some at a higher level than others so an in-depth knowledge of the area was required.

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The Proteomics stand at the Life Sciences open day at the University of Warwick.

MSc Project

Magnetic resonance project with Dr Jozef Lewandowski on "Development of sample preparation methods to study antibody-drug conjugates". Antibody-drug conjugates can be used to directly target infected cells, with minimal side effects. There are currently two such conjugates on the market as an alternative to chemotherapy for cancer treatment. A new way of characterising them especially at an atomic level is needed before they can become more widely available. Sedimentation is a promising avenue and the project centres around the development of an ultracentrifuge tube which the sample can be sedimented in and then directly transferred to an NMR rotor using ultracentrifugation, thus reducing sample loss. Results were very successful and the tubes designed in the project were able to reach 700,000 g in the ultracentrifuge.

Other Academic Work

Undergraduate summer project on "Analysis of Ligand Binding to the Carbohydrate Recognition Domain of DC-SIGNR" in Chemical Biology with Dr Ann Dixon. DC-SIGNR is a c-type lectin which works as part of the immune system but also plays an important role in the spread of the HIV virus through the human body. The carbohydrate recognition domain of DC-SIGNR binds to gp120 on the surface of HIV, but it was unknown whether or not the binding was pH dependent. DC-SIGNR contains LL motifs involved in ligand internalisation but, does not contain YKSL motifs which its sister protein DC-SIGN contains. DC-SIGN using both these motifs is able to internalise its ligand and release it under low pH. The question was therefore raised as to whether the binding of DC-SIGNR is pH dependent or not. In order to answer this, a low pH titration of DC-SIGNR with mannose was done and results were studied using solution-state NMR. The findings are due to be published by Dr Ann Dixon.

Academic Societies

Member of the Royal Society of Chemistry since 2008

Member of the British Mass Spectrometry Society since 2016

Member of the British Society for Proteomic Research since 2019

Member of the American Society for Mass Spectrometry since 2019

Other Interests

Other than working for my PhD I like to spend time going to the gym with other members of MAS and friends from my lab. I watch and play a variety of different sports, read novels and watch anime in my spare time. Baking and other crafts help me to keep calm under the stress of my work. For the past year, I've been teaching myself Italian, but can understand more than I can speak. When I finish my PhD I hope to go and work for the civil service in their labs as a mass spectrometrist.

Georgina

Georgina Charlton

MAS CDT
Senate House
University of Warwick
Coventry
CV4 7AL

g dot charlton at warwick dot ac dot uk