2022

Heparan sulfates are long and highly complex polysaccharide chains found on the cell surface and in the extra cellular matrix. They play a key role in many biological process including cell development, signaling and immune responses but also in pathogenic infections like with SARS-CoV-2. A central step in the biosynthesis of heparan sulfate is the generation of the long glycan backbone, consisting of N-acetylglucosmanine and glucuronic acid units. Two enzymes, EXT1 and EXT2, haven been (...)

The European patent WO2022218997, filed by Pascal Fender’s team (IBS/MEM), protects a universal vaccine platform. Entirely protein-derived and thermostable, it allows the spontaneous and irreversible display of complex antigens using a ’plug and display’ technology. Preclinical studies have shown its efficacy in the field of emerging infectious diseases such as coronaviruses (Chevillard et al., Mol Ther 2022, https://doi.org/10.1016/j.ymthe.2022.02.011) and in oncology in the context of (...)

Malene Jensen, CNRS research director in the “Protein Dynamics and Flexibility” group at the IBS, is one of the 7 researchers in Life Science distinguished by the first Impulscience grant program of the Bettencourt Schueller Fondation. The Foundation is committed to financially support each of these researchers for a period of 5 years and with 2.3 million euros, a sum that covers the research program, a personal bonus for the researcher and the management costs. The work of Malene will allow (...)

Control of ion balance is vital for the cells. It is controlled by membrane ion channels and pumps. The pumps usually use the energy of ATP or light. Microbial rhodopsin (MRs) light-driven ion pumps, are found in a number of microorganisms. MRs can pump various monovalent ions like Na+, K+, Cl-, I-, NO3-. Recently found cyanobacterium Synechocystis sp. halorhodopsin (SyHR) pumps chloride. Scientists from the Membrane Transporters Group of the IBS choose the protein for the studies for (...)

Super resolution microscopy continues to reveal new insights into biology at the nanoscale. Quantitative measurements using super resolution microscopy, however, remain limited due to the highly complex photophysical behavior of the used fluorescent labels. In the case of green-to-red photoconvertible fluorescent proteins (PCFPs), their limited green-to-red conversion efficiency lowers the achievable spatial resolution and causes undercounting errors in quantitative experiments. Researchers (...)

2022 marks the 30th anniversary of the Institut de Biologie Structural and it was celebrated on June 16, 2022. For this special occasion, our annual scientific day took place in the Minactec amphitheater with retrospectives to honor three decades of achievement, as well as a part dedicated to current issues and perspectives. A particular focus was presented on crystallography (after a focus on NMR in 2019 and electron microscopy in 2021). In order to share these presentations with our (...)

Radical chemistry uses high-energy intermediates to carry out difficult reactions or even ones impossible to perform by the so-called polar chemistry. In nature, these reactions are fine-tuned by the structural environment within dedicated enzymes. Radical SAM proteins use an iron-sulfur cluster and S-adenosyl-L-methionine to initiate several radical reactions. These metalloproteins are notably involved in the biosynthesis of numerous cofactors and in the modification of peptides with (...)

In enzymes the "1st coordination sphere" describes the binding of substrate(s) to the active site whereas protein ligands that serve to correctly orient substrate(s) are generally defined as belonging to the "2nd coordination sphere". Protein elements that are found beyond that point, and still can affect catalysis, are part of the "outer coordination sphere". Quinolinate synthase is a good example of this classification because, besides having an active site and residues that accommodates (...)

Polysaccharides of the Glycosaminoglycans (GAGs) family are essential components of cell surfaces and interstitial matrices. Among them, heparan sulfates (HS) are involved in a large number of biological functions, thanks to their ability to bind and regulate a wide array of signaling proteins. These mechanisms are tightly controlled by extracellular enzymes such as HSulf-2 endosulfatase, which modify the structure of HS and their interaction properties. Researchers from IBS (Structure and (...)

Nuclear magnetic resonance (NMR) studies carried out in the 1970s surprisingly demonstrated that aromatic amino acids in proteins can undergo ring rotations (or so-called flips). Paradoxically, these aromatic amino acids are in many cases located in the tightly-packed protein core, where they engage in multiple interactions to maintain the protein fold and thereby function. At that time, it was proposed that large-scale protein “breathing motions” would be necessary in order to accommodate (...)

While mRNA-based vaccine solutions have emerged very quickly to manage the ’COVID-19’ crisis caused by SARS-CoV-2, they have logistical limitations (storage at -20°C, use within 6 hours) that do not allow a large-scale deployment. Moreover, a sterilizing immunity preventing a vaccinated person from transmitting the virus does not exist currently. The IBS ’Adenovirus and Applications’ team led by Pascal Fender designed a non-infectious particle inspired by adenovirus capable of spontaneously and (...)

After AminoCraft*, the entertaining application to memorize the chemical structure of the 20 amino acids, two IBS researchers, Ee de Rosny and Véronique Rossi, associate professors at Université Grenoble Alpes (UGA), in collaboration with Marie-France Breton (Cergy University) have developed MetaboCraft. The new challenge is to reconstitute the metabolic pathways of glycolysis and the Krebs cycle. Like AminoCraft, the goal is to provide a great way for students to have fun while quickly (...)

The SARS-CoV-2 pandemic causes an ongoing global health crisis, which requires efficient and safe vaccination programs. In this study, researchers at the IBS (EBEV, CAID, MEM et M&P groups), in collaboration with IDMIT, Amsterdam University and Institut Pasteur, develop synthetic SARS-CoV2 S glycoprotein-coated liposomes that resemble virus-like particles. Soluble S glycoprotein trimers were stabilized by formaldehyde cross-linking and coated onto lipid vesicles (S-VLP). Immunization of (...)

While vaccines target the molecular mechanisms responsible for infection of the cell via the Spike protein, it is equally important to target the viral replication machinery in patients already infected with the virus. Researchers at the IBS (Protein Dynamics and Flexibility by NMR Group) characterised the nucleoprotein (N) of SARS-CoV-2, the most abundant protein produced by the virus. This protein has numerous functions that are essential for viral infection, including protection of the (...)