Work Package 4

WP4: Experimental characterization of the membrane-drug and membrane-protein systems

Deliverables

  • D4.1 : Experimental markers of conformation changes in membrane-protein and membrane-drug complexes. [due month 36]
  • D4.2 : Progress report 2. [due month 36]
  • D4.3 : Mid-term meeting.

Houston, USA, Apr 2017

WP4: Secondments, transfer of knowledge, networking

Secondments to USA : Ukraine to US (2), Estonia (1)

Training:

  • Mastering techniques of preparing unilamellar liposomes with given lipid composition for subsequent spectroscopic studies;
  • Study of the influence of 2D nanoparticles on viability and cytotoxicity of the drugs, mastering corresponding techniques.

Results and knowledge transfer:

  • Liposome preparation techniques transferred to Ukrainian team.
  • Obtained liposomes with different composition and registered their VIS spectra.
  • Cytotoxicity effect of 2D membranotropic nanoparticles is evaluated.

Dissemination:

  • Lab seminar in US

WP4: Secondments, transfer of knowledge, networking

Secondments to Ukraine: From Estonia (2), Latvia (1), France (3)

Training and knowledge transfer:

• Learning about possible ways of commercialization in MRCENTER

• Providing MRCENTER the current results of the project and its strategic goals

• Discussion about possible ways of using project results in the area of 2D materials covered by lipids and other biological molecules (area of expertise of MRCENTER and its US partners)

Lipid deposition on Graphene substrate: “Structures of single, double and triple layers of lipids adsorbed on graphene: Insights from all-atom molecular dynamics simulations”, Carbon 118 (2017) 358-369.

WP4: Current progress – spectroscopy and structural methods

  • IR and Raman spectra of single lipids on gold enhancing substrate are characterized
  • IR and Raman spectra of lipid mixtures on gold enhancing substrate are obtained and analyzed
  • Fluorescent and Raman studies of Pt drugs with membranes and nanoparticle carriers are obtained
  • Reliable Raman spectra of lipid liposomes in liquid are recorder
  • Structural studies of artificial lipid membranes by X-ray and neutron reflectivity techniques.

WP4: Current progress – membrane proteins

  • Crowding effects of integral membrane proteins. Spectral and kinetic changes accompanying the assembly of the light-harvesting 1 (LH1) complex with the reaction center (RC) complex into monomeric RC-LH1 and dimeric RC-LH1-PufX core complexes of the photosynthetic purple bacterium Rhodobacter (Rba.) sphaeroides were systematically studied over the temperature range of 4.5-300K.
  • The role of hydrogen bonds in stabilisation of the photosynthetic reaction centre membrane proteins against hydrostatic high pressure. Using the native pigment cofactors as local probes, we investigated the response to external hydrostatic high pressure of the RC membrane protein complexes from the non-sulphur photosynthetic bacterium Rba. sphaeroides.
  • Quantum chemical modelling of the reaction centre structure and spectra. Several different quantum chemical and molecular dynamic methods were used to optimize the RC structures and to calculate their spectroscopic properties, both in the electronic ground state and in first excited singlet state.

WP4: Dissemination

Publications:

  1. Freiberg, A.; Chenchiliyan, M.; Rätsep, M.; Timpmann, K. (2016). Spectral and kinetic effects accompanying the assembly of core complexes of Rhodobacter sphaeroides. Biochimica et Biophysica Acta, 1857 (11), 1727−1733, 10.1016/j.bbabio.2016.08.001.
  2. Chenchiliyan, M.; Timpmann, K.; Jalviste, E.; Adams, P.G.; Hunter, C.N.; Freiberg, A. (2016). Dimerization of core complexes as an efficient strategy for energy trapping in Rhodobacter sphaeroides. Biochimica et Biophysica Acta, 1857, 634−642, dx.doi.org/10.1016/j.bbabio.2016.03.020.
  3. Timpmann, K.; Kangur, L.; Lõhmus, A.; Freiberg, A. (2017) High-pressure modulation of the structure of the bacterial photochemical reaction center at physiological and cryogenic temperatures J. Phys. B: At. Mol. Opt. Phys. 50 144006: https://doi.org/10.1088/1361-6455/aa77e4.
  4. Kangur, L.; Jones, M.R.; Freiberg, A. (2017). Hydrogen bonds in the vicinity of the special pair of the bacterial reaction Enter probed by hydrostatic high-pressure absorption spectroscopy Biophysical Chemistry, in press: https://doi.org/10.1016/j.bpc.2017.04.003.

WP4: Expenses

Secondments

  • Ukraine: 2*2000 EUR + 2*1000 (travel from Ukraine to USA is expensive)
  • Estonia: 2000 EUR
  • France: 3*2000 EUR/person-month
  • Latvia: 1*2000 EUR/person-month

This project has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No 690853