Enzyme Inhibitors | Photopharmacology | Molecular Imaging Probes
Research Summary
Our research focuses on the design and development of small-molecule tools that advance fundamental biological understanding and enable new therapeutic strategies. We specialise in enzyme inhibition, photopharmacology, and molecular imaging, combining synthetic chemistry with chemical biology to create highly selective and controllable probes.
We develop inhibitors for several medically important enzymes, including RET, LCK, BTK, pyruvate kinase liver isoform (PKL), and N-myristoyltransferase (NMT). These compounds are used both to investigate disease-relevant biological pathways and as starting points for potential drug development. Many of our inhibitors are designed to be photoswitchable or fluorescent, enabling activity to be precisely controlled or monitored with light.
In parallel, we develop molecular imaging probes, such as fluorescent nucleic-acid base analogues (FBAs) and advanced multiphoton microscopy dyes, which allow high-resolution visualisation of nucleic acids and cellular processes. Together, these projects aim to deliver powerful chemical tools that deepen insight into cellular mechanisms and support the development of future therapeutic approaches.
Enzyme Inhibitors (EI)
Rearranged during transfection (RET) is a receptor tyrosine kinase that plays a crucial role in the development of the nervous system and kidneys. It is also involved in various cancers and developmental disorders. Despite extensive research, there are still several knowledge gaps regarding RET kinase. These gaps can be broadly categorized into biological, pathological, and therapeutic aspects. Our research focuses on the design of selective RET inhibitors, including photoswitchable DFG-out inhibitors that allow external control over kinase activity.
Collaborators include Andréasson, Lundbäck and CBCS.
Design and Development of Photoswitchable DFG-Out RET Kinase Inhibitors. Yongjin Xu, Chunxia Gao, Måns Andreasson, Liliana Håversen, Marta Carrasco, Cassandra Fleming, Thomas Lundbäck, Joakim Andréasson and Morten Grøtli. Eur. J. Med. Chem. 2022, 234, 114226.
Design and Development of a Photoswitchable DFG-Out Kinase Inhibitor. Yongjin Xu, Chunxia Gao, Liliana Håversen, Thomas Lundbäck, Joakim Andréasson and Morten Grøtli. Chem. Commun. 2021, 57, 10043.
Lymphocyte-specific protein tyrosine kinase (LCK) is a Src-family kinase crucial for T-cell development, signalling, and activation. Despite significant progress, important mechanistic questions remain regarding LCK function and regulation. We develop fluorescent and photoswitchable LCK inhibitors, enabling light-controlled activity and real-time visualisation of inhibitor binding.
Collaborators include Andréasson, Lundbäck and CBCS.
All-Photonic Kinase Inhibitors: Light-Controlled Release-and-Report Inhibition. Cassandra L. Fleming, Carlos Benitez-Martin, Elin Bernson, Yongjin Xu, Linnea Kristenson, Tord Inghardt, Thomas Lundbäck, Fredrik B. Thorén, Morten Grøtli and Joakim Andréasson. Chem. Sci. 2024, 15, 6897.
A Fluorescent LCK Inhibitor that Exhibits Diagnostic Changes in Emission Upon Binding the Kinase Enzyme, Cassandra Lee Fleming, Patrick A Sandoz, Tord Inghardt, Björn Önfelt, Morten Grøtli, Joakim Andreasson. Angew. Chem. Int. Ed., 2019, 58, 15000 –15004.
Pyruvate kinase liver isoform (PKL) is a key enzyme in glycolysis, catalysing the conversion of phosphoenolpyruvate (PEP) to pyruvate while generating ATP. As a central regulator of hepatic glucose metabolism, PKL plays an important role in maintaining metabolic balance. Our work focuses on developing chemical tools, including allosteric modulators and fluorescent probes, to investigate how PKL functions and how its activity is regulated. These compounds allow us to probe the enzyme’s mechanism, structural dynamics, and metabolic roles in greater detail.
Collaborators include Boren and Hyvonen.
Potent Fluorescent Probe for Target-Engagement Studies of Allosteric Pyruvate Kinase Modulators.
Fluorescent binding assay for allosteric ligands of liver pyruvate kinase. Oscar Nilsson, Agnieszka Bogucka, István Köteles, Liliana Håversen, Sara Liljenberg, Mikael Rutberg, Marko Hyvönen, and Morten Grøtli. Eur. J. Med. Chem. 2025, 298,117989.
N-myristoyltransferase (NMT) is an enzyme that catalyzes the covalent attachment of myristic acid, a 14-carbon saturated fatty acid, to the N-terminal glycine residue of proteins. This modification is essential for the proper functioning of various proteins, including those involved in signal transduction, membrane targeting, and protein-protein interactions. NMT has emerged as a promising target for antimalarial drug development due to its crucial role in the survival and pathogenicity of Plasmodium spp., the parasites responsible for malaria.
Collaborators include Staker, Kaushansky and Sunnerhagen.
Exploring subsite selectivity within Plasmodium vivax N-myristoyltransferase using pyrazole-derived inhibitors. Diego Rodríguez-Hernández, Michael K. Fenwick, Rachael Zigweid, Banumathi Sankaran, Peter J. Myler, Per Sunnerhagen, Alexis Kaushansky, Bart L. Staker and Morten Grøtli. J. Med. Chem. 2024, 67, 7312.
Identification of potent and Selective N-myristoyltransferase inhibitors of Plasmodium vivax liver stage hypnozoites and schizonts. Diego Rodríguez-Hernández, Kamalakannan Vijayan, Rachael Zigweid, Michael K. Fenwick, Banumathi Sankaran, Wanlapa Roobsoong, Jetsumon Sattabongkot, Elizabeth K.K. Glennon, Peter J. Myler, Per Sunnerhagen, Bart L. Staker, Alexis Kaushansky, Morten Grøtli. Nat. Commun. 2023, 14, 5408.
Bruton’s tyrosine kinase (BTK) is a non-receptor tyrosine kinase central to B-cell receptor signalling and immune regulation. Aberrant BTK activity is linked to several immunological disorders and cancers.
We are developing selective BTK-targeting probes for labelling the enzyme in live cells, enabling real-time visualisation and mechanistic studies. In parallel, we design new covalent-inhibitor warheads to improve selectivity, reactivity, and overall probe performance, supporting both chemical biology and therapeutic exploration.
Collaborators include Malmerberg and Boren.
Design and application of a fluorescent probe for imaging of endogenous Bruton’s tyrosine kinase with preserved enzymatic activity. Anna P. Valaka, Hampus Nyström, Liliana Håversen, Carlos Benitez-Martin, Clara Schäfer, Woo Suk Jang, Alessandro Camponeschi, Joakim Andréasson, Jan Borén and Morten Grøtli. RCS Chem Biol., 2025, 6, 618.
Photopharmacology (PP)
Lack of probe selectivity is a recurrent problem in pharmacological treatments and is caused by the inability to control the activity of the probe in time and space. We are addressing this issue by incorporating photo-responsive groups (photoswitches and photolabile protecting groups) into the molecular structure of kinase inhibitors. These inhibitors allow for the use of light to externally control activity, which can be delivered with very high spatiotemporal precision.
Collaborators include: Andréasson and König.
All-Photonic Kinase Inhibitors: Light-Controlled Release-and-Report Inhibition. Cassandra L. Fleming, Carlos Benitez-Martin, Elin Bernson, Yongjin Xu, Linnea Kristenson, Tord Inghardt, Thomas Lundbäck, Fredrik B. Thorén, Morten Grøtli and Joakim Andréasson. Chem. Sci. 2024, 15, 6897.
A Fluorescent LCK Inhibitor that Exhibits Diagnostic Changes in Emission Upon Binding the Kinase Enzyme, Cassandra Lee Fleming, Patrick A Sandoz, Tord Inghardt, Björn Önfelt, Morten Grøtli, Joakim Andreasson. Angew. Chem. Int. Ed., 2019, 58, 15000 –15004.
Molecular Imaging Probes (MIP)
Molecular imaging probes are agents used to visualize, characterize and quantify biological processes in living systems.
Fluorescent nucleic acid base analogs (FBAs) are structural analogs of the standard DNA/RNA bases, which are highly fluorescent, and form Watson-Crick hydrogen bonds with complementary bases. We are developing FBAs for studying structure and dynamics of nucleic acids.
Collaborators include: Wilhelmsson and Lemurell.
Pentacyclic adenine: a versatile and exceptionally bright fluorescent DNA base analog, Mattias Bood, Anders F. Füchtbauer, Moa S. Wranne, Jong Jin Ro, Sangamesh Sarangamath, Afaf H. El-Sagheer, Déborah L. M. Rupert, Rachel Fisher, Steven W. Magennis, Anita C. Jones, Fredrik Höök, Tom Brown, Byeang Hyean Kim, Anders Dahlén, L. Marcus Wilhelmsson and Morten Grøtli. Chem. Sci., 2018, 9, 3494 – 3502.
Multiphoton microscopy is a benchmark tool in biomedical research, used for the fluorescence imaging in cellular environments. This has important implications for disease diagnosis and the monitoring of therapy response.
In conventional two-photon microscopy the fluorescence intensity of the employed molecular probe is proportional to the square of the excitation light intensity, implying that the fluorescence from the sample is confined around the focal point, yielding good spatial resolution. The spatial resolution can be dramatically improved by drawing on higher-order processes such as four photon absorption.
As a part of an EU funded project entitled Breaking the Resolution Limit in Two-Photon Microscopy Using Negative Photochromism (4for2), we are developing molecules that combine two mechanistically entangled two-photon processes for the generation of a fluorescence output. This is possible by merging two-photon absorption, two-photon FRET-induced photoisomerization, and negative photochromism.
Collaborators include Andréasson, Pischel and Hofkens.