Lab news

Studying protein conformation using a new cyclic ion mobility mass spectrometry (cIMMS) device

Dr Konstantinos Thalassinos

We are the first group to publish a paper on how a new cyclic ion-mobility mass-spectrometry (cIMMS) device, manufactured by Waters, can be used to probe protein structure and dynamics. In particular, the tandem ion mobility capabilities of the instrument allow us to probe in very fine detail protein unfolding pathways and for the first time to do so for co-existing and interconverting conformers. We are now using this technology to study proteins involved in protein misfolding diseases such as human amyloid islet polypeptide.

The paper is:
Eldrid, C.; Ujma, J.; Kalfas, S.; Tomczyk, N.; Giles, K.; Morris, M.; Thalassinos, K. Gas Phase Stability of Protein Ions in a Cyclic Ion Mobility Spectrometry Traveling Wave Device. Anal. Chem. 2019, 91 (12), 7554–7561 https://doi.org/10.1021/acs.analchem.8b05641

A video where I and other people in the field describe the cIMMS technology:
https://vimeo.com/318178536/005117727e

The link to the Waters site:
https://www.waters.com/waters/en_US/SELECT-SERIES-Cyclic-IMS-ion-mobility-mass-spectrometer/nav.htm?cid=135021297&locale=en_PT

 

Posted by ublmcr01 in Lab news, News, Publications, Uncategorised

Arrival of the new Multiwavelength Beckman Optima analytical ultracentrifuge at the UCL Molecular Interactions Facility

We are very grateful to the UCL Capital Equipment Fund for the purchase of the new Beckman AUC Optima for the UCL Molecular Interactions Facility that arrived on 25th March 2019. This was installed after Easter and is starting to become operational. This is the first machine of its type to be installed permanently at an UK university. The pictures show (1) the arrival of the instrument on wheels, (2) what we found when the boxes were opened, and (3) the big smiles of our user community. The major development with this new AUC machine is the capability to measure macromolecular sedimentation across a full absorbance wavelength range, and not with a single wavelength as with the old Beckman AUC Proteome. Other advantages are the capacity to measure samples that are more dilute than with the old AUC. The instrument is highly complementary in scope to macromolecular data collected by NMR, crystallography, mass spectrometry, calorimetry and X-ray and neutron scattering. This should make a big difference to biophysical studies where measuring monodispersity or dissociation constants Kd values are important. For example, the binding of ligands with different chromophores can be monitored simultaneously but independently of the protein that they bind to. In the study of heterogeneous interactions, protein complexes in which one is labelled and the other is not can be monitored in detail, or likewise proteins with haem groups that absorb strongly in the visible region. We have already completed with Dr Lindsay McDermott (pictured) an interesting first project where different fatty acids with two distinct fluorescently-tagged chromophores bind to a lipid binding protein called zinc alpha2 glycoprotein. An account of how this method can be used to follow DNA or RNA binding to a protein at three wavelengths for DNA/RNA, protein and their complex is reported in a short review by Borries Demeler on the new multiwavelength AUC published in the current issue of the Biochemist, published by our Biochemical Society: http://www.portlandpresspublishing.com/sites/default/files/biochemist/Biochemist%20Biophysics/BioAPR19_All%28Demeler%29.pdf?dm_i=4WUK,532Y,250YBQ,HPBK,1

Do please email Prof Steve Perkins (s.perkins@ucl.ac.uk) or Mr Jayesh Gor (J.gor@ucl.ac.uk) if you are interested in discussing possibilities, or even applying this new instrument for your research.

          

Posted by ublmcr01 in Lab news, News, Uncategorised

Single-Molecule Studies at the ISMB Biophysics Centre

Single-molecule studies can reveal key molecular behaviours that are difficult or impossible to discern at the ensemble level. At the ISMB Biophysics Centre, we are planning trials of new, user-friendly instruments that enable the measurement of protein localisation, conformation, mass and force at the single-molecule level.

If your research would benefit from any of these technologies, please contact us. As well as yielding preliminary data for your research, your samples could help to win funding to bring these instruments to the Biophysics Centre on a permanent basis.

The three instruments that will be trialled are:

  • A Nanoimager: a user-friendly super-resolution microscope (https://oni.bio/) for cellular imaging, particle tracking (for diffusion or active transport) or single-molecule FRET studies.
  • An interferometric scattering mass spectrometer (iSCAMS) (https://www.aragobio.com/), that uses light scattering to determine the macromolecular weight of single particles. This is a powerful way of determining the oligomeric state or composition of protein complexes for structural biology projects, with very limited sample requirements (only tens of nM and microliters required).
  • A combined optical tweezer and single-molecule imaging setup (https://lumicks.com/) for detailed mechanistic studies of forces and kinetics.

For informal enquires, do not hesitate to contact Tina Daviter (t.daviter@mail.cryst.bbk.ac.uk) or Mark Williams (m.williams@mail.cryst.bbk.ac.uk). Other ISMB members with experience/interest in these areas who are happy to discuss are: Alan Lowe (a.lowe@ucl.ac.uk), Phil Robinson (p.robinson@mail.cryst.bbk.ac.uk) and Anthony Roberts (a.roberts@mail.cryst.bbk.ac.uk 

– Dr Tina Daviter

Posted by ubcg49z in Lab news, News