Probing the Conformation of Gas Phase Biomolecular Ions by Forster Resonance Energy Transfer and Ion Mobility Mass Spectrometry
Event details
| Date | 12.11.2015 |
| Hour | 16:30 › 17:30 |
| Speaker |
Prof. Philippe Dugourd Institut Lumière Matière CNRS & Université Lyon 1, France |
| Location | |
| Category | Conferences - Seminars |
Structural measurement in the gas phase is fueled by developments in the mass spectrometry community to carry out “native” electrospray ionization to obtain gas-phase biomolecular ions with a conformation that is presumably close to the native one. In Lyon, we try to push Mass Spectrometry and Optics beyond traditional areas to understand the structure and aggregation of proteins.
Förster resonant energy transfer (FRET) is a strongly distance sensitive optical method and can be used as a “spectroscopic ruler” to obtain distance constraints within a molecule. The transposition of this technique to the gas phase is appealing since it opens the perspective of combining the structural accuracy of FRET with the specificity and selectivity of mass spectrometry. During this talk, we will present a methodology for measuring FRET in the gas-phase based on the detection of specific photo-fragmentation rather than fluorescence. The structural sensitivity of the method was tested using chromophores grafted on a series of small alanine based peptides.1
Small oligomers of the amyloid beta protein have been implicated as the neurotoxic agent leading to Alzheimer's disease, and in particular mutations in the hydrophobic core region comprising amino acids L17 to A21 have a large influence on the propensity for aggregate formation. In order to understand the origin of this behavior, the gas phase conformations for the different charge states of the wild-type 12–28 fragment of the amyloid beta and its F19P alloform were studied by a combination of action-FRET, ion-mobility spectrometry (IMS) and molecular dynamics simulations.2 Ongoing experiments on proteins will also be discussed.
Finally, we have just achieved the construction of a new experimental set-up which couples tandem-IMS with laser excitation.3 This set-up allows to record optical spectra on isomer selected biomolecular ions. The Influence of charge localization on the conformation and on the optical spectrum of a small peptide will be presented.
1 S. Daly, F. Poussigue, A.-L. Simon, L. MacAleese, F. Bertorelle, F. Chirot, R. Antoine and P. Dugourd. Anal. Chem. 86, 8798–8804 (2014).
2 S. Daly, A. Kulesza, F. Poussigue, A.-L. Simon, C.-M. Choi, G. Knight, F. Chirot, L. MacAleese, R. Antoine and P. Dugourd. Chem. Sci. 6, 5040 –5047 (2015).
3 A.-L. Simon, F. Chirot, C.-M. Choi, C. Clavier, M. Barbaire, J. Maurelli, X. Dagany, L. MacAleese and P. Dugourd. Rev. Sci. Instrum. 86, 094101 (2015).
Förster resonant energy transfer (FRET) is a strongly distance sensitive optical method and can be used as a “spectroscopic ruler” to obtain distance constraints within a molecule. The transposition of this technique to the gas phase is appealing since it opens the perspective of combining the structural accuracy of FRET with the specificity and selectivity of mass spectrometry. During this talk, we will present a methodology for measuring FRET in the gas-phase based on the detection of specific photo-fragmentation rather than fluorescence. The structural sensitivity of the method was tested using chromophores grafted on a series of small alanine based peptides.1
Small oligomers of the amyloid beta protein have been implicated as the neurotoxic agent leading to Alzheimer's disease, and in particular mutations in the hydrophobic core region comprising amino acids L17 to A21 have a large influence on the propensity for aggregate formation. In order to understand the origin of this behavior, the gas phase conformations for the different charge states of the wild-type 12–28 fragment of the amyloid beta and its F19P alloform were studied by a combination of action-FRET, ion-mobility spectrometry (IMS) and molecular dynamics simulations.2 Ongoing experiments on proteins will also be discussed.
Finally, we have just achieved the construction of a new experimental set-up which couples tandem-IMS with laser excitation.3 This set-up allows to record optical spectra on isomer selected biomolecular ions. The Influence of charge localization on the conformation and on the optical spectrum of a small peptide will be presented.
1 S. Daly, F. Poussigue, A.-L. Simon, L. MacAleese, F. Bertorelle, F. Chirot, R. Antoine and P. Dugourd. Anal. Chem. 86, 8798–8804 (2014).
2 S. Daly, A. Kulesza, F. Poussigue, A.-L. Simon, C.-M. Choi, G. Knight, F. Chirot, L. MacAleese, R. Antoine and P. Dugourd. Chem. Sci. 6, 5040 –5047 (2015).
3 A.-L. Simon, F. Chirot, C.-M. Choi, C. Clavier, M. Barbaire, J. Maurelli, X. Dagany, L. MacAleese and P. Dugourd. Rev. Sci. Instrum. 86, 094101 (2015).
Practical information
- General public
- Free
Organizer
- ISIC Physical Chemistry Seminars
Contact
- Dr Frank van Mourik