LINXS Event - 2nd Membrane Protein Workshop

7 Dec 2021, 12:30 → 8 Dec 2021, 12:45 Europe/Stockholm

                                                                                                                                

The Membrane Protein Working Group is dedicated to explore the unique challenges involved in research on the structural biology of membrane proteins. In our first online workshop in May 2021, we discussed several aspects of expression systems, protein purification, membrane solubilization and other preparation methods. Our winter workshop is the continuation to further explore topics related to the “Structural Resolution of Membrane Proteins: From Sample Preparation to Structural Resolution”.

The production of high-quality membrane protein crystals is always very challenging so we continue to cover more topics like multi-protein complexes, detergent trials and crystallization strategies such as LCP and Hi-LIDE. We will also invite scientists to introduce their best practices on Cryo-EM or neutron structures, scattering techniques, and data collection and processing.

In the spring we welcomed more than 200 participants from PhD students to senior researchers from a range of disciplines. Due to the new directions of the corona situation we have now decided to make this event fully digital as well. We kindly ask PhD students and postdocs to submit a short abstract if they are interested in giving a short talk. 

Where: on Zoom
When: December 7th – 8th (noon-to-noon) CET 2021
Abstract submission deadline: 25th November 2021
Registration deadline: 1st December 2021
Workshop fee: Digital participation - No fee

Preliminary Programme

Day 1: Sample Preparation, Quality Control

• Multi-protein complexes, lipid-protein / enzyme-ligand interactions, orphan receptors

• Membrane solubilization and other preparation methods

• Detergent trials and functional characterization

• Crystallisation techniques such as LCP and Hi-LIDE

• Confirmed speakers: Maria Marta Garcia Alai (EMBL, Hamburg), Petra Fromme (Arizona State University), Gisela Brändén (University of Gothenburg),

Day 2: Output/Structural Resolution

• Serial crystallography

• Electron diffraction

• X-ray/Neutron scattering, X-ray crystallography for large proteins

• Data collection and processing, molecular dynamics and new softwares

• SEC-SAXS to study MP-detergent interaction

• Confirmed speakers: Christian Löw (EMBL Hamburg), Alessandra Luchini (PSI), Erik Lindahl (Stockholm University)

 

During our events we sometimes take photographs and short film clips to profile our activities. Please let us know if you don’t want to be in any photos/films before we start the event. Some talks are recorded to be used for educational purposes in the LINXS website.

By registering to our events you give your permission to LINXS, according to the General Data Protection Regulation (GDPR), to register your name and e-mail address to be used for the sole purpose of distributing newsletters and communications on LINXS activities.

Tuesday 7 December

13:00 → 13:05 Welcome and purpose of the workshop

13:05 → 13:45 Keynote talk - Sample optimisation and characterisation of Membrane proteins

Speaker: Maria Marta Garcia Alai

13:45 → 14:05 Contr. talk 1 - Design and characterization of a new generation of amphipols for solubilizing and stabilizing membrane proteins

Speaker: Manuela Zoonens

14:05 → 14:10 Break

14:10 → 14:50 Keynote talk - Intestinal peptide and drug uptake – a structure perspective

Nutrient uptake across the lipid bilayer is essential for life. Membrane transporters with specialized functions have evolved to maintain the nutrient homeostasis of cells. Many of those are energized by an electrochemical proton gradient. Prominent members of such ’secondary active transport system’ are the oligopeptide transporters PepT1 and PepT2. Both belong to the Solute Carrier Family 15 (SLC15), which is highly conserved among all phyla of life. They are known to play key roles in human diseases and impact the pharmacokinetic profiles of orally administered drug molecules. I will highlight the approaches that allowed us to structurally characterize this transporter family. We studied transporter homologs (from bacteria to humans) by structural (X-ray crystallography, SAXS, and cryo-EM), biochemical and biophysical approaches, and determined the molecular basis for ligand recognition. The transporter has been captured in different conformations allowing us to obtain a molecular picture of the transport cycle.

Speaker: Christian Löw

14:50 → 15:10 Contr. talk 2 - Single particle cryo-EM structure of human AQP7 adopting the formation of dimer of tetramers

Speaker: Peng Huang

15:10 → 15:30 Contr. talk 3 - Combination of SAS techniques for modeling detergent/IMP interactions

Speaker: Francoise Bonneté

15:30 → 15:40 Break

15:40 → 16:00 Contr. talk 4 - Structural characterization of transpeptidase sortase enzyme from oral pathogen Streptococcus sanguinis

Speaker: Smita Yadav

16:00 → 16:40 Keynote talk - Time-resolved fs crystallography: Discoveries and challenges

Speaker: Petra Fromme

16:40 → 17:05 General discussion

Wednesday 8 December

09:00 → 09:40 Keynote talk - XFEL- and synchrotron-based serial crystallography studies of the membrane-bound proton pump cytochrome c oxidase

Speaker: Gisela Brändén

09:40 → 10:00 Contr. talk 5 - Structural Characterization of a Cholesterol-producing Enzyme - Squalene Monooxygenase

Speaker: Emilie Müller

10:00 → 10:40 Keynote talk - Models of biological membranes: complex lipid composition and membrane proteins

Biological membranes are mainly composed of lipids and proteins. Unfortunately, the complex composition of biological membranes prevents their direct investigation with biophysical methods. Therefore, most physico-chemical and biophysical studies on biological membranes rely on simple models composed of lipid bilayers including only 1-3 lipid species and in fewer cases membrane proteins. Among all, supported lipid bilayers represent suitable systems to mimic the lipid component of biological membranes and allow for structural and dynamic investigations by means of several surface sensitive techniques. However, loading membrane proteins with controlled orientation in a supported lipid bilayer remains a challenge in this field.[1]
Recently, we showed the preparation and characterization of lipid bilayers including either complex lipid mixtures, i.e. lipid extract from the yeast Pichia Pastoris, or membrane proteins. Supported lipid bilayers with or without membrane proteins were prepared by a recently developed protocol. The method is based
on the application of peptide-discs [2], a specific kind of nanodiscs where the protein belt is composed by self-assembled 18A peptide molecules. The peptide discs can be adsorbed on the hydrophilic surface of the solid support and since the formation of the 18A belt is reversible, they can be disassembled by rinsing with fresh buffer solution. We showed that this method can successfully lead to the production of supported lipid bilayer with biologically relevant lipid compositions [3] and also to the incorporation of membrane protein with asymmetric structure, i.e. composed by one large extramembrane domain (EMD) a transmembrane domain (TMD).[4]
References:
[1] G. Fragneto et al., Current Opinion in Colloid & Interface Science, 2018, 38, 108-121.
[2] S. R. Mitdgaard et al., Soft Matter, 2014, 10, 738-752.
[3] A. Luchini et al., Anlytical Chemistry, 2020, 92, 1, 1081-1088.
[4] A. Luchini et al., JCIS, 2021, 585, 376-385.

Speaker: Alessandra Luchini

10:40 → 10:50 Break

10:50 → 11:10 Contr. talk 6 - Structural investigation of TSPO translocator combining SANS and ab initio simulation

Speaker: Sophie Combet

11:10 → 11:50 Keynote talk - Unraveling the gating of ligand-gated ion channels through cryo-EM, SANS, electrophysiology & molecular simulations

Speaker: Erik Lindahl

11:50 → 12:15 General discussion

12:15 → 12:20 Closing remarks