GLUT4 extraction using poly(styrene-co-maleic acid): A test of functionality using biotinylated bis-glucose photoaffinity labelling.

Abstract

Membrane proteins are notoriously difficult to extract, purify and characterise, due to their fragility once removed from their bilayer environment. This fragility stems from their amphipathic nature. Traditionally, detergent-mediated methods have been used to isolate membrane proteins. However, the resulting micelles formed are liable to cause denaturation, mis-folding, and essentially inactivity of the membrane protein. An alternative method has been recently studied; using poly (styrene-co-maleic acid) (SMA) to form stable nanodiscs for membrane
protein extraction. Studies have shown great potential for a wide range of applications using polymer-nanodiscs to study membrane proteins previously inaccessible with detergent-derived methods. However, the study of functionality of membrane proteins in nanodisc formations have only just begun. In this study, integral membrane proteins, glucose transporter 4 (GLUT4) and glucose transporter 1 (GLUT1), are investigated to understand their functionality using
two biotinylated-bis-glucose compounds when solubilised in SMA-nanodiscs. Results suggest low efficiency in protein binding. Most probably caused by either protein inactivity within the nanodisc, or through steric hindrance of the nanodisc itself. Further investigation could allow the activity of GLUT proteins to be further understood, when solubilised with SMA.

Date of Award	12 Dec 2018
Original language	English
Awarding Institution	University of Bath
Supervisor	Karen Edler (Supervisor), Paul Whitley (Supervisor), Gareth J Price (Supervisor) & James Doutch (Supervisor)