Emma Wood

Methodologies to Overcome the Size Limitation in Cryogenic Electron Microscopy

About me

I came to Leeds in 2018 where I started my degree in biology. Here I found I had an interest in molecular and structural biology (and a slight hatred for plant science). After this I stayed in Leeds and completed a masters in molecular medicine, where my project which focused on determining the roles of CSMD1 in cancer. I then moved home to Manchester where I worked at Qiagen as a Technical Assistant for just under a year while I was applying for PhDs. Here I worked on a team to develop new PCR kits which meant my time at Qiagen was mainly spent doing qPCRs. While I loved my time working in industry, I missed the freedom and flexibility of working in academia, and this further motivated me to peruse a PhD. I can now confidently say I prefer working on my project and hope to never have to see another qPCR again.

My Project

Cryogenic electron microscopy (cryo-EM) has been integral for determining the 3D structure of a large range of molecules and providing information for structural-based drug design. However, the use of cryo-EM is currently limited to molecules above 40kDa, due to small molecules having low signal-to-noise ratio and often having no identifiable features. Recent studies have investigated ways to overcome this limitation by increasing the molecular weight. This has been done using nanobodies, Designed Ankyrin Repeat Proteins (DARPins), and a range of fusion techniques. While all techniques have been shown to be promising, common problems with these methods include flexibility, preferred protein orientation, and potential clashes with the target. Additionally, these techniques are limited to nanobody and DARPin availability. The aim of my project is to develop a methodology which is applicable to a variety of small proteins in cryo-EM. This will be carried out using Affimers®, a Leeds born non-antibody-binding protein. The use of Affimers® has several advantages over alternative methods due to protein stability and engineering. The molecular weight of the ~12kDa Affimers® will be increased through synthesised binders, adding around 50-100kDa onto the target protein. By increasing the overall molecular weight of the target, we aim to overcome the obstacles of threshold limits in Cryo-EM.

Connect

LinkedIn: https://www.linkedin.com/in/emmal-wood