Welcome and purpose of the workshop

Keynote talk - Sample optimisation and characterisation of Membrane proteins

• Maria Marta Garcia Alai

Contr. talk 1 - Design and characterization of a new generation of amphipols for solubilizing and stabilizing membrane proteins

• Manuela Zoonens

Keynote talk - Intestinal peptide and drug uptake – a structure perspective

• Christian Löw

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.

Contr. talk 2 - Single particle cryo-EM structure of human AQP7 adopting the formation of dimer of tetramers

• Peng Huang

Contr. talk 3 - Combination of SAS techniques for modeling detergent/IMP interactions

• Francoise Bonneté

Contr. talk 4 - Structural characterization of transpeptidase sortase enzyme from oral pathogen Streptococcus sanguinis

• Smita Yadav

Keynote talk - Time-resolved fs crystallography: Discoveries and challenges

• Petra Fromme

Keynote talk - XFEL- and synchrotron-based serial crystallography studies of the membrane-bound proton pump cytochrome c oxidase

• Gisela Brändén

Contr. talk 5 - Structural Characterization of a Cholesterol-producing Enzyme - Squalene Monooxygenase

• Emilie Müller

Keynote talk - Models of biological membranes: complex lipid composition and membrane proteins

• Alessandra Luchini

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.

Contr. talk 6 - Structural investigation of TSPO translocator combining SANS and ab initio simulation

• Sophie Combet

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

• Erik Lindahl

Closing remarks