Polish scientists from Wrocław and Warsaw are working on fluorescent probes to track two SARS-CoV-2 enzymes in live cells which are key for the multiplication of its particles and infecting more cells These solutions will enable better and more effective testing of, i.a., antiviral drugs inhibiting the enzymes.
The research project is financed by the Foundation for Polish Science from EU funds under the Smart Growth Operational Programme (SGOP) as part of the extension of grants obtained within the TEAM programme by Professor Marcin Drąg from the Department of Biological Chemistry and Bioimaging of the Wrocław University of Science and Technology and Professor Daniel Gryko from the Institute of Organic Chemistry of the Polish Academy of Sciences in Warsaw. Both scholars are also the laureates of the Foundation for Polish Science Prize.
The key proteases
The pandemic-inducing coronavirus SARS-CoV-2 consists of 29 different proteins. Among them are two specialised proteins responsible, i.a., for the virus replication, i.e. the multiplication of its particles and spreading to other cells in the body of the infected person. The proteins, also called proteolytic enzymes (proteases) are SARS-CoV-2-Mpro and SARS-CoV-2-PLpro. The SARS-CoV-2-Plpro protease also impacts the human immunological system and blocks the body’s defence mechanisms against coronavirus. The team of Professor Marcin Drąg has been the first in the world to discover the functioning of both enzymes in a very short time. Thanks to that we are familiar with their structure, the compounds with which each of them binds, and the binding sites. This, in turn, makes it possible to find compounds which selectively block the activity of these enzymes and stop the multiplication of the virus. “Such compounds may become drugs combating the virus not only very effectively but also safely, as they only inhibit the activity of the coronavirus SARS-CoV-2 proteases, without any impact on the activity of human enzymes,” said Professor Marcin Drąg.
Professor Drąg’s team’s discovery of the mechanisms of coronavirus SARS-CoV-2 proteases in such a short time by Drąg’s team was possible thanks to close cooperation with several other scientific groups in the world, and primarily thanks to the fact that scientists from Wrocław (as part of the ongoing TEAM grant) developed unique technologies for the fast identification and precise analysis of proteolytic enzymes. The next goal is to develop methodology enabling the monitoring of the activity of the SARS-CoV-2-Mpro and SARS-CoV-2-PLpro proteases in human cells. This will make it possible to monitor the percentage of cells attacked by the virus and find out whether drugs designed for inhibiting these enzymes actually inhibit them, and if so, how effective they are. In order to reach this goal, Professor Marcin Drąg started cooperation with Professor Daniel Gryko, an expert in the field of functional dyes. Professor Gryko’s team (as part of the TEAM grant) deals with discovering new-generation fluorescent dyes characterised by an exceptional durability and a high fluorescence intensity. These compounds are subsequently used in fluorescence microscopy.
The effectiveness of observations needs to be increased
Contemporary fluorescence microscopy makes it possible to create high-resolution images of processes taking place in live cells and to study these processes. In order to carry out observations with the use of cutting-edge fluorescence microscope, particles able to absorb at the same time light and fluorescence are needed. They are often referred to as fluorophores, dyes or probes. Fluorophores are attached to the object which is to be made visible under the microscope, e.g. the virus protease, which makes it possible to observe its activity. Currently fluorophores are available, which enable the imaging of the SARS-CoV-2-Mpro and SARS-CoV-2-Plpro proteases, however, their sensitivity is insufficient to perform accurate research. “The perfect fluorophore making it possible to visualise the SARS-CoV-2 proteases in cells with high sensitivity should be small, so that its attachment to the protease does not impair its activity. Furthermore, it must be characterised with a high fluorescence intensity and the ability to absorb light. Our task is to develop a new class of fluorophores meeting all these three conditions,” explained Professor Daniel Gryko.
A chance for rapid commercialisation
“The objective of our joint research is to design fluorescent probes for detecting SARS-CoV-2 proteases and testing them, so that they could become commercially available as soon as possible, i.e. within a dozen or so months, to substantially contribute to combatting the COVID-19 pandemic,” the scientists emphasised.
The project is financed with EU funds from the European Regional Development Fund under the Smart Growth Operational Programme (SGOP). The funds in the amount of PLN 4 million (PLN 2 million for each research team) were awarded as part of the thematic competition for funding new research tasks associated with the COVID-19 pandemic conducted by the Foundation for Polish Science. The competition’s total budget was PLN 15 million. The funds were awarded for 14 projects.
- On the research conducted by Professor Marcin Drąg on the SARS-CoV-2-PLpro protease
- On the research conducted by Professor Marcin Drąg devoted to the SARC-COV-2_Mpro protease
The TEAM programme is implemented by the Foundation for Polish Science with EU funds from the European Regional Development Fund under the Smart Growth Operational Programme, Axis IV: Increasing the research potential, Measure 4.4 Increasing the human potential in the R&D