Case Study: Jisoo Jean

JJ read Biology at Imperial College London, where she explored different subjects of interest, from systems neuroscience to plant pathology. During her undergraduate degree, she undertook varied research internships from immunohistochemistry of patient samples in hospital laboratories to imaging zebrafish models of tuberculosis. It was not until her final year research project on the characterisation and crystallisation of a biofilm-attenuating protein that she discovered her interest in protein biochemistry. 

Having just worked on biofilm proteins and having secured a place on the Interdisciplinary Bioscience DTP (iCASE), she undertook a research position at the Wyss Institute for Biologically Inspired Engineering at Harvard. Her research there was a serendipitous merger of her undergraduate project and her upcoming DPhil research: using bacterial superglues to engineer biologically active materials. Using SpyTag and SpyCatcher, spontaneous isopeptide bond-forming protein partners, she functionalised biofilms for rhizosphere manipulation. After this spell in Boston, she came to Oxford for the first year of the DTP. 

In her first year, she developed relevant skills and was trained in mathematics, statistics, basic programming, bioinformatics and data management at the Doctoral Training Centre (DTC). As an iCASE student, she had applied to a given project hosted by the Howarth lab in the Department of Biochemistry and AB Vista, so she did not undertake rotation projects and started her DPhil research straight away.

Her project focuses on conferring thermal resilience to enzymes. Since enzymes are proteins, they are denatured upon heating, which cannot be bypassed or prevented in most industrial processing. This makes most naturally occurring enzymes unfit for industrial application prior to engineering for greater thermostability. Her industrial partner, AB Vista, is a market leader in the global animal feed industry and is the second largest purveyor of phytase. Phytase breaks down phytic acid, the primary form of phosphate storage found in plant-based foods, which functions as an anti-nutrient to chelate minerals and essential ions and reduce feed digestibility. Phytase administration to animal feed not only improves digestibility but reduces environmental phosphate pollution to facilitate sustainable agricultural practices. 

The SnoopLigase system was developed by the Howarth lab, and comprises of SnoopTagJr and DogTag, two peptide tags that are irreversibly conjugated by SnoopLigase. Using this system, she cyclised model enzyme beta-lactamase and phytase to confer thermal resilience. The SnoopLigase-cyclised enzymes were significantly more thermally resilient than their uncyclised counterparts, and retained activity and solubility even after boiling. Her work was published in the Journal of the American Chemical Society, and she was awarded the 2018 DTP Impact Award for Enterprise and Innovation.

Her current work focuses on developing a modular platform for enzyme cyclization to confer drastic improvements in thermal resilience to a wide range of enzymes. Such a platform will enable the quick stabilisation of enzymes for industrial application by bypassing the labour-intensive and time-consuming mutation screening process currently used. She hopes to implement this platform on an industrial scale during her placement with AB Vista, which she will be undertaking in 2020. 

Alongside her research, she has been committed to teaching, science communication and outreach. She has been a demonstrator for the biochemistry undergraduates at Oxford for the past two years, and has demonstrated for the UNIQ summer school. She has also participated in local science festivals and continues to be a PhD tutor with the Brilliant Club, a non-profit organisation that serves to increase the number of students from under-represented backgrounds that progress to highly selective universities. She aims to complete the Developing, Learning and Teaching (DLT) programme during her DPhil to better consolidate her teaching experiences.