Semisynthesis and application of homogeneous prion proteins with complex posttranslational modifications

• Applicant: Professor Dr. Christian Friedrich Wilhelm Becker
• Subject Area: Biochemistry
• Term: from 2011 to 2014
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 196792226

The prion protein (PrP) is a unique protein-based pathogen that causes rare diseases in humans such as Kuru and Creutzfeld-Jakob. The structural and biochemical manifestations of these diseases are based on ordered protein aggregation, a mechanism that is common to many prevalent human diseases. Prion toxicity is not well understood but membrane attachment via its GPI anchor is crucial in this respect. We will apply existing methods and develop new tools for the incorporation of glycans and GPI anchors into PrP and thereby generate access to well defined preparations of this complex posttranslationally modified protein. Different variants of well defined glycosylated and GPI-anchored PrPs will be used to study the effect of membrane association, localization, folding and changes in interaction schemes as well as to identify the molecular basis of ordered PrP aggregation. The tools developed here will help to elucidate the influence of posttranslational modifications, specifically of glycosylation and lipidation at one or more amino acid residues in PrP, which can lead to dramatic changes in biophysical properties, interaction schemes and localization. In order to study such different PrP isoforms, robust approaches are required for the production of protein variants with complex posttranslational modifications. Access to these protein isoforms is one of the major challenges in protein biochemistry today, since diversification of the human proteom by posttranslational modifications (PTMs) increases the number of protein variants by one to two orders of magnitude when compared to the number of genes encoding for proteins.

• DFG Programme: Research Grants
• International Connection: Austria
• Major Instrumentation: Peptide Synthesizer
• Instrumentation Group: 1160 Synthese-Apparaturen der Biochemie