CEEPC/IPM/CMSC - Abstrakt prezentace

(4. konference České společnosti pro hmotnostní spektrometrii - PL-1)
Uncovering molecular details of protein "misfolding - aggregation" using affinity- and ion mobility- mass spectrometry - Physiological and “Parkinson”- Synucleins

Michael Przybylski 1 *

  1. University of Konstanz

Abstrakt

A large variety of cellular processes are based on the formation and dynamics of multi- and supramolecular protein assemblies, and several diseases are characterised by “misfolded” protein aggregates. Mass spectrometry (MS) is often unsuitable to direct analysis of reaction pathways and intermediates in aggregation. Ion mobility- MS (IM-MS) has been emerging as a new tool for analysis of protein aggregation due to its concentration-independent gas phase separation capability. First applications of IM-MS to the in vitro oligomerization of α-synuclein (αSyn) and ß-amyloid (Aß), key proteins for Parkinson’s and Alzheimer’s disease, enabled the identification of hitherto unknown degradation and aggregation products. Time dependent sstudies of the in vitro oligomerization provided first identification of a specific autoproteolytic fragmentation, particularly a highly aggregation-prone fragment by cleavage at V71/T72 in the ß-breaking triplett VVT(70-72) in the central aggregation domain [1].The corresponding recombinant αSyn(72-140) fragment showed substantially faster aggregation and neurotoxicity compared to the intact protein. The recent development of combined bioaffinity-MS methods [2] enabled first direct (top-down) structural studies in vivo. Applications of affinity-MS will be discussed using epitope-specific αSyn- antibodies [3] for the characterization of oligomers and interactions in vivo. Specific mutations of the central (70-72) triplet in synucleins, and affinity-MS provided breakthrough results, e.g. mutation of the VFS(70-72) triplet from physiological ßSyn into αSyn completely abolished neurotoxic aggregation [4]. These results suggest ion mobility-MS as powerful tools for the molecular elucidation of structures and intermediates of polypeptide aggregation.

* Korespondující autor: Michael.Przybylski@uni-konstanz.de

Literatura

  1. Vlad C. et al.: Chem. Biochem. 12, 2740-2744 (2011).
  2. Dragusanu M., et al.: J. Am. Soc. Mass Spectrom. 21, 1643-1648 (2010).
  3. McLaurin J., et al.: Nature Med. 8, 1263-1269 (2002).

Partneři společnosti

LabRules LCMS LabRules GCMS

Partneři

Bruker HPST Merck Pragolab Amedis EastPort Shimadzu Waters