Chemical probes for the study of carbohydrate-active enzymes

Background

Carbohydrates play many roles in cells from all kingdoms of life. In addition to their well-known role as an energy source, they also have important functions in, for example, communication between cells, cell-pathogen interactions, intracellular signalling, and maintaining a stable cellular environment. The various sugar building blocks are often linked together to create glycans of very complex and diverse structures. They can also be linked to other biomolecules such as proteins, a modification referred to as glycosylation. Since glycans are not directly genetically encoded, their levels and structures are dynamic and at any given time the exact composition of glycans is dictated by the networks of cellular enzymes that create and modify them. Defects in the functioning of one of these enzymes often leads to disease, however the mechanisms by which the malfunctioning of individual enzymes leads to specific pathologies are often poorly understood.

In our group we focus on the development of novel chemical tools to advance our understanding of carbohydrate biology: in specific we are interested in studying how specific carbohydrate-processing enzymes work, both at the molecular level as well as in terms of their functioning in a cellular environment and their role in pathology. This project contributes to our work program by designing, synthesising and testing novel enzyme probes for application in structural biology and/or cell biology experiments.

Objectives

The specific form of glycosylation that our group is interested in is O-mannosylation, the modification of cell-surface proteins with a glycan in which the first sugar, linked to protein hydroxyl groups, is a mannose residue. In this project, you will focus on a set of enzymes responsible for the biosynthesis of O-mannosylated proteins. You will develop substrate analogues as tools to study these enzymes, either by inhibiting their function or by enabling unnatural functionalities to be introduced that allow us to characterise and visualise the chemical process catalysed by the target enzyme in vitro or inside cells. The project is of a multidisciplinary nature and will be tailored to your specific experience, interests and training aspirations. For example, the synthesised probes may be tested in living cells, on isolated proteins in vitro, or in combination with structural protein work.

Training

Working on this project, you will be able to strengthen your knowledge and skills in a variety of methods and techniques in synthetic chemistry, cell biology, molecular biology, biochemistry and/or protein crystallography. Specifically, depending on the exact nature of the project, you may be exposed to project specific training in cloning, bacterial and/or mammalian cell culture, protein expression in either of these systems, enzyme activity assays, SDS-PAGE and immunoblotting, affinity purification, mass spectrometry analysis, fluorescence microscopy and/or FACS, in addition to the various analytical techniques associated with organic synthesis such as HPLC purification, LCMS and NMR characterization.

In addition, all research students follow our innovative Doctoral Training in Chemistry (iDTC): cohort-based training to support the development of scientific, transferable and employability skills. All research students take the core training package which provides both a grounding in the skills required for their research as well as transferable skills to enhance employability opportunities following graduation. Core training is progressive and takes place at appropriate points throughout a student’s higher degree programme, with the majority of training taking place in Year 1.

Equality and Diversity

The Department of Chemistry holds an Athena SWAN Gold Award and is committed to supporting equality and diversity for all staff and students. The Department strives to provide a working environment which allows all staff and students to contribute fully, to flourish, and to excel.

Your background
You should expect hold or expect to achieve the equivalent of at least a UK upper second class degree in Chemistry or a related subject. Please check the entry requirements for your country: https://www.york.ac.uk/study/international/your-country/