Oxidative folding of disulfide-rich cone snail toxins

Main area:Protein chemistry
Target group:Biochemistry, Molecular Biomedicine, Biology
Educational level:Masters, Bachelor
Project description:

Predatory marine cone snails are amazing creatures that kill their prey – fish, worms or other snails – by injecting them with a deadly mixture of hundreds of different disulfide-rich neuropeptides referred to as conotoxins. Conotoxins selectively target specific subtypes of receptors or ion channels throughout the nervous system, a characteristic that has lead to wide use of conotoxins in ion channel research and as therapeutic agents. The fact that conotoxins generally contain many disulfide-bonds make them hard to produce – when synthesized as linear peptides, refolding often results in misfolding because cysteines do not form native disulfide-bonds.

We have found that cone snails have evolved a hypervariable family of conotoxin-specific PDIs (csPDIs) that assist the formation of disulfide-bonds in conotoxins. We now established a recombinant expression system in E. coli that allows the production and subsequent molecular characterization of a variety of conotoxins and other disulfide-rich peptides of biomedical or research interest.

Depending on the specific project, the work will cover experimental methods within protein biochemistry, biophysics, and molecular biology such as protein expression in E. coli, protein purification using a variety of chromatography techniques, different in vitro assays and spectroscopical methods to characterize protein structure and function, protein structure determination (in collaboration), and Western blotting. In addition, we are now initiating work to identify molecular targets for specific conotoxins, a project for which we need to establish a variety of new assays/methods.

Many (!) different projects are available at different levels (Bachelor, Master, PhD) – for more details, just contact Lars for an informal meeting.

Project home page: http://www1.bio.ku.dk/english/research/bms/research/pbg/groups/le/research/
Supervisor(s): Lars Ellgaard
Email:lellgaard@bio.ku.dk