Periodic Reporting for period 1 - MS SPIDOC (Mass Spectrometry for Single Particle Imaging of Dipole Oriented protein Complexes)
Reporting period: 2018-09-01 to 2019-08-31
MS SPIDOC will overcome this data challenge by developing a native mass spectrometry (MS) system for sample delivery, named X-MS-I. It will provide mass and conformation selected biomolecules, which are oriented along their dipole axis upon imaging. This will enable structural reconstructions from much smaller datasets speeding up the analysis time tremendously. Moreover, the system features low sample consumption and a controlled low background easing pattern identification.
The main objectives of the project are:
• Deliver mass and conformation separated biomolecules for SPI.
• Orient proteins for SPI.
• Image protein complex unfolding.
• Exploit potential of protein orientation for other applications.
The MS SPIDOC consortium combines internationally leading expertise in different fields relevant to the project. First designs of components for mass and conformation selection as well as efficient sample introduction are currently being tested. Results are in line with our requirements. Protein orientation is investigated theoretically. Electric fields theoretically facilitating dipole orientation have been achieved on an orientation device. We expect that the device can benefit other gas phase applications and are investigating the potential. A technical design report for implementation of the prototype at European XFEL has been filed. Individual components will be assembled in the next period and tested prior to SPI experiments.
The first 4 scientific deliverables have been submitted:
D1.1 Stability range and charge distribution of electrosprayed ions
D2.1 Ion optical models of devices
D2.2 Construction of transfer interface & digital trap
D3.1 Instrumental settings for structural integrity
D1.1 and D3.1 also feed into milestone 1, evaluation of structure conservation. Based on available IM and action-FRET data as well as simulations, we expect that protein structures are sufficiently stable in the gas phase. The results will be extended to a range of standards in order to select the best settings for unknown samples based on similar sized standards.
First generations of components (aerolens, digital filter and ion trap, ion mobility, orientation device) have been assembled and are undergoing testing now. In sum, component development and testing for X-MS-I is well under way. Moreover, recommendations for structural preservation have been defined and will be extended in the near future. Protein orientation indeed appears feasible and we plan on exploiting its potential for other applications soon.
First publications are in preparation. Main impact is expected in the second period, when X-MS-I prototype becomes available and designed components will be exploited for marketing potential.