Current Group

Scientific Experimental officer

Dr. Nic Mullin

Email: n.mullin@sheffield.ac.uk

Project: My main interest is developing scanning probe instrumentation for studying soft matter and biology. I am currently working as a researcher on "Next generation AFM for solving problems in biology and medicine" funded by the Wellcome Trust, on which I am co-investigator with Jamie. I also manage the day-to-day running of the BICEN AFM lab.

Post-Doctoral Research Associates

Dr. Xinyue Chen

Email: xinyue.chen@sheffield.ac.uk

Website: https://orcid.org/0000-0001-6987-5540

Project: I have been heavily committed to the studies of mechanobiology covering multiple length scales for almost a decade. Currently I'm engaged in the characterisations of the mechanical architectures of both complex tissue (breast cancer metastasis in bone microenvironment) and supramolecular composite (cell wall of S. Aureus) mainly by using atomic force microscopy (AFM). These characterisations are essential for understanding the crucial role of mechanics in biological processes. The instrumental and theoretical developments involved in these studies are helpful in extending the application of high resolution mechanical mapping by AFM to research on length scales that have yet to be accessed.

Abimbola Feyisara Adedeji

E-mail: a.adedeji@sheffield.ac.uk

Website: https://www.linkedin.com/in/abimbola-feyisara-adedeji-36a46437/

Project: I am utilising high resolution atomic force microscopy to profile, investigate and quantify the inherent structural motifs and topographical properties associated with peptidoglycan harvested at the exponential phase of different methicillin-resistant Staphylococcus Aureus (MRSA) and the Escherichia coli (E.coli) derivatives.

Here are some of the research questions that I seek to address; 1) how does resistant changes the cell wall architecture? 2) Can we distinguish the antimicrobial strains based on the material properties of their associated cell wall? And 3) what is the link between these architectural differences and the inherent macroscopic resistant expressed by the aforementioned strains? This will reveals the imprints of resistant on the peptidoglycan architecture and bring-to-light the structure-function correlates associated with the aforementioned strains. This study will yields more understanding as to how antimicrobial resistant impacts on the cell wall architecture and mechanics, leading to promising designs for antibiotics that can circumvent resistant in bacteria.

Laia Pasquina Lemonche

E-mail: lpasquinalemonche1@sheffield.ac.uk

Website: https://www.linkedin.com/in/laia-pasquina-l/

Project: The battle against Antimicrobial Resistance is currently one of the World Health Organisation priorities. My project adds to this research by exploring one fundamental question: How do antibiotics work? We know some of the most commonly used antibiotics disrupt the Cell Wall of Bacteria (in specific a molecule called Peptidoglycan). However, we do not know enough about the 3D architecture of this macromolecule.

We are using a combinations between microbiology experiments and imaging using high-resolution AFM to understand the architecture of the cell wall from Gram-positive bacteria such as Staphylococcus aureus and Bacillus subtilis. Once we have developed a new model of 3D architecture of Peptidoglycan for S. aureus and B. subtilis, we have also studied crucial mutants and different strains. Then, by comparing these pool of images from "healthy bacteria" with bacteria treated with b-lactam antibiotics, we could elucidate more knowledge into the process of killing bacteria. I am in the final stage of writing my thesis with a continuation project as a Research Asisstant in Hobbs and Foster labs.

PhD Students

Anaam Alomari

E-mail: aaalomary1@sheffield.ac.uk

Twitter: @enaam_o

PhD commenced: 2018

Second Supervisor: Prof. Simon Foster (Molecular Biology and Biotechnology)

Project: My project aims to make a local mechanical measurement on the bacterial cell wall and to use AFM to study the mechanism of antibiotics resistance. As an initial stage in this investigation, the

cell wall of MRSA bacteria has been investigated through comparison with sensitive S. aureus, and alive cells of Bacillus subtilis are studying to find the structure-mechanical function relationship in the cell wall and the whole cell. B.subtilis was used of these cells could be controlled more than Staphylococcus aureus during the imaging process with measure the aim to the cell wall mechanical properties of the whole cell and the cell wall then find the structure-mechanical function relationship.

Vinny Verma

E-mail: vverma1@sheffield.ac.uk

Website: www.linkedin.com/in/vinny-verma

PhD commenced: 2017

Second Supervisor: Prof. Jon R. Sayers (Department of Infection, Immunity and Cardiovascular Disease)

Project: DNA polymerases synthesize the complementary DNA strands from a DNA template. It’s 5’ exonuclease domain (Flap endonuclease), plays an important role in DNA replication, repair and recombination. It is responsible for the removal of 5’ branch on the lagging strand of DNA during replication. Aspects of how FENs locate their branched DNA substrates and the conformational changes associated with DNA hydrolysis remain unclear and progress in this direction could greatly improve the field of medicine and biotechnology.

AFM is a high-resolution imaging technique that enables molecular and sub-molecular resolution imaging in liquid environments, allowing biological systems to be visualized at the molecular scale under physiological conditions. AFM can allow us to know how FENs process their substrate and what conformational changes occur during the reaction. Dynamic AFM imaging provides the advantage of allowing imaging in biological conditions, compared to other imaging techniques. Hence, it gives us the opportunity to understand the physical aspects of the FEN catalysed reaction, thus complement the biological information already available. We hope to formulate a method of single molecular dynamic imaging to understand the interactions between DNA and DNA regulating proteins in general.

If you are interested in joining our research group, please find any current positions here or feel free to contact us.