ARIA will be unavailable on the morning of Tuesday 29th April 2025 due to scheduled maintenance. Please plan work accordingly.
InstructThe latest webinar in the Instruct-ERIC Structure Meets Function series this month includes speakers who have accessed cutting-edge structural biology services through Instruct. The webinar series offers an insight into the very cutting edge of structural biology research, utilising the latest techniques available through Instruct-ERIC facilities and centres.
We will hear from Stefano Morasso of Elettra in Italy, who has recently completed an Instruct internship at IBS Grenoble, Instruct-FR2. We also have a talk from Celia Romao of ITQB NOVA, part of the Instruct-PT Research Site, who accessed the Weizmann Institute in Israel for their research.
Registration for the webinar is open, book your place here.
Speaker 1: Stefano Morasso, Elettra
Talk Title: Boosting drug repurposing applying a multi-technique approach. A case study on SARS-CoV2 PLpro
Abstract: The SARS-CoV-2 papain-like protease (PLpro) is a crucial target for antiviral drug development due to its role in viral replication and immune evasion. Despite extensive research, the development of PLpro-specific inhibitors has been hindered by the redox-sensitivity of the enzyme and the unspecific nature of previously reported compounds. To date, only GRL-0617 has proven to be a chemical scaffold leading to the development of powerful inhibitors.
This study, started within the EU’s granted Exscalate4CoV project and now continued within the AVITHRAPID partnership, aimed to identify novel PLpro inhibitors through a rigorous screening and validation process. We employed a comprehensive approach, including enzymatic assays, direct-binding studies, and cellular assays, to ensure the specificity and efficacy of identified compounds. The critical revision inherent in our validation pipeline during primary screening is a key strength of this study, as it enabled the exclusion of redox-sensitive false positives. Our findings revealed a novel non-covalent inhibitor, CPI-169 that demonstrated micromolar range inhibition of PLpro's proteolytic activity. Ligand-observed NMR experiments confirmed CPI-169's competitive binding with GRL-0617, suggesting a similar binding site, highlighting its potential as a promising scaffold. Ongoing protein-observed NMR at the Instruct-ERIC centre in Grenoble (IBS) on CPI-169 as well as other candidate inhibitors aims to provide detailed interaction insights for improved PLpro-targeting antiviral drug design.
Speaker 2: Celia Romao, ITQB NOVA
Talk Title: Electron-Dense granules as strategic metal stores for coping with stress stimulus
Abstract: Electron-dense granules (EDGs) are known to exist within bacteria, and play a key role as intracellular metal reservoirs. We have been investigating the function of electron dense granules in the radiation resistant bacteria Deinococcus radiodurans. Using X-ray fluorescence nano-imaging data (ID16A-NI and ID16-B beamlines at ESRF), we analyzed the metal content in these compartments. Our results show that EDGs are elemental-rich regions, particularly with phosphorous, calcium and manganese under control conditions, and that these elements are mobilized in response to stress. To gain deeper molecular and structural insights, we performed Cryo-STEM coupled with Electron Dispersive X-ray Spectroscopy (EDS) on the D. radiodurans cells, which was performed in the INSTRUCT–ERIC center at Weizmann Institute, Israel (https://instruct-eric.org/platform/electron-microscopy-weizmann-institute-israel/). The results reveal a heterogeneous metal composition across different cells, suggesting that EDGs contribute to a dynamic stress-responsive mechanism of metal regulation within the bacterial population. Acknowledgments: European Union's Horizon 2020 research and innovation programme under grant agreement No 857203- IMpaCT - Imaging life from Molecules to cells - building knowledge on Cryo-electron microscopy methodologies at ITQB NOVA – www.itqb.unl.pt/impact. Cryo-electron microscopy studies received partial support from the Weizmann Institute of Science (The Irving and Cherna Moskowitz Center for Nano and BioNano Imaging), and from the European Union (ERC-AdV grant, CryoSTEM, 101055413 to ME). This work benefited from access to the Weizmann Institute Electron Microscopy Unit, an Instruct-ERIC centre through the Access proposal PID: 19879. The image analysis of Cryo-EM images was made available thanks to the de Picciotto Cancer Cell Observatory in Memory of Wolfgang and Ruth Lesser of the MICC Life Sciences Core Facilities at the Weizmann Institute of Science. FCT Project: PTDC/BIA-BQM/31317/2017. We acknowledge the European Synchrotron Radiation Facility for the X-ray fluorescence imaging (XRF) at ID16B with the proposal LS-3037.
