Skip to content

Proteins are the so-called workhorses of the cell. Although their quantity can be accurately analysed by advanced mass spectrometry techniques, some features of proteins are still hidden, such as their activity state, ability to bind drugs, or certain post-translational modifications. The goal of the project »Chemical Probes« is to gain insight into the importance of these processes in biomedical questions using a chemical proteomics approach.

Researchers use synthetic chemistry to design and synthesise chemical probes for the covalent modification of proteins. The aim is to enable or enhance their analysis. Specifically, chemical probes can aid in the identification of novel drug targets and their binding sites. They can also help in visualising the location of diseased tissue. With novel chemical probes aimed against proteases, a class of enzymes capable of breaking up proteins, but also the proteins themselves, the project intends to facilitate novel strategies for biomarkers and drug development, particularly the identification of targets for drugs.

Project goals

Overall, the aims of the project are:

  1. The development of novel synthetic strategies and novel chemical probes

  2. The application of these probes for the detection of proteases and other enzymes

The project has a specific focus on target identification by tandem mass spectrometry making use of cleavable linker strategies. Cleavable linkers attach the protein of interest to the chemical probe – but in a way that the two can easily be separated again. Thus the cleavable linkers help separate the cargo (protein of interest) from the vehicle (chemical probe).The project also looks at the application of chemical probes in imaging.

The chemical probes that are being developed in this project contain different types of detection tags: fluorophores for (high-resolution) fluorescence microscopy and alkyne”mini-tags” for bioorthogonal chemistry - high-yielding chemical reactions that can occur in living cells without perturbing their normal chemistry. These alkyne detection tags are only two atoms in size and minimise cell permeability issues. They are amenable to the click chemistry-mediated introduction of any desired tag. Additionally, the alkyne group enables coherent anti-stokes raman scattering (CARS) microscopy imaging of the targets without functionalisation by a large fluorophore, which can influence the chemical properties and bioactivity of the molecule.

Chemical probes for aspartic proteases

Through synthetic chemistry, researchers at ISAS have developed reagents that can modify complex natural products into chemical probes. They also managed to devise novel chemical probes for aspartic proteases, a small, but biomedically important class of proteases. Despite representing a small number of proteases, aspartic proteases play an important role in human physiology and pathological processes. For example, presenilin is the catalytic component of the gamma-secretase complex, which is associated with Alzheimer’s disease. It is also an emerging target in cancer therapy, because of its involvement in the signalling pathway involved in malignant cell growth and cell death (Notch signalling).

In addition, aspartic proteases of infectious agents are attractive drug targets, such as human immunodeficiency virus (HIV) protease as well as plasmepsins from the malaria-causing parasite Plasmodium falciparum. The novel chemical probes will help further characterise the roles of these enzymes. Through the design and full solid-support synthesis of probes that bind to their target in response to activation by light (photoaffinity labelling probes), aspartic proteases can be covalently labelled and detected on gel or by mass spectrometry.

Biomarker for breast cancer

In breast cancer cells, the scientists detected another aspartic protease, cathepsin D. It has been linked to poor prognosis in breast cancer and is a potential biomarker. The researchers also found potential interaction partners. In addition, they discovered that sequestosome-1, a protein involved in the degradation of cells (autophagy), is a cathepsin D substrate. The chemical probes could help to shed light on this degradation pathway in the future.

www.verhelstlab.net

Share

Select publications

ChemBioChem, Vol. 24, No. 21, 2023, P. e202300444

Verhelst S, Prothiwa M.

Chemical Probes for Profiling of MALT1 Protease Activity

https://doi.org/10.1002/cbic.202300444

ChemBioChem, Vol. 24, No. 1, 2023, P. e202300418

Yang J, Carvalho LA, Ji S, Chen S, Moreira R, Verhelst S.

4-Oxo-β-Lactams as Novel Inhibitors for Rhomboid Proteases

https://doi.org/10.1002/cbic.202300418

Organic & Biomolecular Chemistry, Vol. 21, No. 32, 2023, P. 6498-6502

Ji S, Verhelst S.

Furin-targeting activity-based probes with phosphonate and phosphinate esters as warheads

https://doi.org/10.1039/d3ob00948c

ACS Omega, Vol. 8, No. 28, 2023, P. 25487-25495

Korovesis D, Gaspar VP, Beard HA, Chen S, Zahédi RP, Verhelst SHL.

Mapping Peptide-Protein Interactions by Amine-Reactive Cleavable Photoaffinity Reagents

https://doi.org/10.1021/acsomega.3c03064

Angewandte Chemie (International ed. in English), Vol. 62, No. 29, 2023, P. e202305093

Li B, Su K, Van Meervelt L, Verhelst SHL, Ismalaj E, De Borggraeve WM, Demaerel J.

Ex situ Generation of Thiazyl Trifluoride (NSF3 ) as a Gaseous SuFEx Hub

https://doi.org/10.1002/anie.202305093

ACS Chemical Biology, Vol. 18, No. 4, 2023, P. 686-692

Chen S, Liang C, Li H, Yu W, Prothiwa M, Kopczynski D, Loroch S, Fransen M, Verhelst SHL.

Pepstatin-Based Probes for Photoaffinity Labeling of Aspartic Proteases and Application to Target Identification

https://doi.org/10.1021/acschembio.2c00946

ACS Chemical Biology, Vol. 18, No. 3, 2023, P. 456-464

Kahler JP, Aloi VD, Aliaga JM, Kerselaers S, Voets T, Vriens J, Verhelst SHL, Barniol-Xicota M.

Clotrimazole-Based Modulators of the TRPM3 Ion Channel Reveal Narrow Structure-Activity Relationship

https://doi.org/10.1021/acschembio.2c00672

Israel Journal of Chemistry, Vol. 63, No. 3-4, 2023

Yang J, Korovesis D, Ji S, Kahler JP, Vanhoutte R, Verhelst S.

Efficient Synthesis of an Alkyne Fluorophosphonate Activity-Based Probe and Applications in Dual Colour Serine Hydrolase Labelling

https://doi.org/10.1002/ijch.202200094

Chemical Science, Vol. 14, No. 7, 2023, P. 1666-1672

Vanhoutte R, Barniol-Xicota M, Chiu W, Vangeel L, Jochmans D, De Jonghe S, Zidane H, Barr HM, London N, Neyts J, Verhelst SHL.

Azapeptide activity-based probes for the SARS-CoV-2 main protease enable visualization of inhibition in infected cells

https://doi.org/10.1039/d2sc04147b

Biomolecules, Vol. 13, No. 2, 2023

Houdou M, Jacobs N, Coene J, Azfar M, Vanhoutte R, van den Haute C, Eggermont J, Daniels V, Vangheluwe P, Verhelst SHL.

Novel Green Fluorescent Polyamines to Analyze ATP13A2 and ATP13A3 Activity in the Mammalian Polyamine Transport System

https://doi.org/10.3390/biom13020337

International Journal of Molecular Sciences , Vol. 24, No. 3, 2023

Sun J, Ru J, Ramos-Mucci L, Qi F, Chen Z, Chen S, Cribbs AP, Deng L, Wang X.

DeepsmirUD: Prediction of Regulatory Effects on microRNA Expression Mediated by Small Molecules Using Deep Learning

https://doi.org/10.3390/ijms24031878

Neuropathology and Applied Neurobiology, Vol. 49, No. 1, 2023, P. e12877

Phan V, Hathazi D, Preusse C, Czech A, Freier E, Shema G, Zahedi RP, Roos A.

Molecular mechanisms in chloroquine-exposed muscle cells elucidated by combined proteomic and microscopic studies

https://doi.org/10.1111/nan.12877

Journal of Medicinal Chemistry, Vol. 65, No. 20, 2022, P. 13660-13680

Codony S, Entrena JM, Calvó-Tusell C, Jora B, González-Cano R, Osuna S, Corpas R, Morisseau C, Pérez B, Barniol-Xicota M, Griñán-Ferré C, Pérez C,…

Synthesis, In Vitro Profiling, and In Vivo Evaluation of Benzohomoadamantane-Based Ureas for Visceral Pain

https://doi.org/10.1021/acs.jmedchem.2c00515

ACS Medicinal Chemistry Letters, Vol. 13, No. 7, 2022, P. 1144-1150

Vanhoutte R, Verhelst SHL.

Combinatorial Optimization of Activity-Based Probes for Acyl Protein Thioesterases 1 and 2

https://doi.org/10.1021/acsmedchemlett.2c00174

Chemical Science, Vol. 13, No. 8, 2022, P. 2270-2279

Li B, Voets L, Van Lommel R, Hoppenbrouwers F, Alonso M, Verhelst SHL, De Borggraeve WM, Demaerel J.

SuFEx-enabled, chemoselective synthesis of triflates, triflamides and triflimidates

https://doi.org/10.1039/d1sc06267k

Journal of Materials Chemistry B, Vol. 40, 2021, P. 8512-8517

Yang L, Chen S, Yi D, Chen Q, Zhang J, Xie Y, Sun H.

Synthesis and fluorescence properties of red to near-infrared emitting push-pull dyes based on benzodioxazole scaffolds

https://doi.org/10.1039/D1TB01189H

Cell Death and Differentiation, 2021, P. 230-245

Rufo N, Korovesis D, Van Eygen S, Derua R, Garg AD, Finotello F, Vara-Perez M, Rozanc J, Dewaele M, de Witte PA, Alexopoulos LG, Janssens S,…

Stress-induced inflammation evoked by immunogenic cell death is blunted by the IRE1α kinase inhibitor KIRA6 through HSP60 targeting

https://doi.org/10.1038/s41418-021-00853-5

RSC Chemical Biology, Vol. 2, No. 4, 2021, P. 1285-1290

Kahler JP, Verhelst SHL.

Phosphinate esters as novel warheads for activity-based probes targeting serine proteases

https://doi.org/10.1039/d1cb00117e

ChemBioChem, Vol. 22, No. 13, 2021, P. 2206-2218

Korovesis D, Beard HA, Mérillat C, Verhelst SHL.

Probes for Photoaffinity Labelling of Kinases

https://doi.org/10.1002/cbic.202000874

ChemBioChem, Vol. 22, No. 9, 2021, P. 1578-1581

Yang J, Mendowicz RJ, Verhelst S.

Tagged benzoxazin-4-ones as novel activity-based probes for serine proteases

https://doi.org/10.1002/cbic.202000848

Molecular Omics, Vol. 17, No. 2, 2021, P. 197-209

Beard HA, Korovesis D, Chen S, Verhelst SHL.

Cleavable linkers and their application in MS-based target identification

https://doi.org/10.1039/d0mo00181c

RSC Advances, Vol. 11, No. 7, 2021, P. 4196-4199

Van Kersavond T, Konopatzki R, van der Plassche MAT, Yang J, Verhelst SHL.

Rapid synthesis of internal peptidyl α-ketoamides by on resin oxidation for the construction of rhomboid protease inhibitors

https://doi.org/10.1039/d0ra10614c

Further projects

3D Molecular Pathology

The aim of the work carried out by researchers in the »3D molecular pathology« project is to gain a better understanding of the influence of inflammatory cells on the course of diseases that trigger massive immune reactions.

Biochemical Annotations of Mass Spectrometry Imaging Data for Worldwide Exchange

The research groups AMBIOM and Spatial Metabolomics are working together to develop a plug-in for the multi-dimensional imaging software napari that makes it possible to visualise and biochemically annotate MSI data.

Creating 'Leibniz Mass Spectral Imaging Library' for Identification of Primary & Secondary Metabolites

The project aims at creating the first-ever open-access MSI library of over 1000 bioactive compound standards on different matrix-assisted laser desorption/ionization (MALDI) MSI platforms.

Synthesis, Structure & Biological Effects of Ultrasmall (1–2 nm) Bimetallic Silver-Platinum Nanoparticles

In the »Synthesis, Structure & Biological Effects of Ultrasmall (1–2 nm) Bimetallic Silver-Platinum Nanoparticles« project, ISAS researchers are examining the antimicrobial activities of nanoparticles.

TRR 332 – Neutrophil Granulocytes: Development, Behaviour & Function

At ISAS, scientists in the subproject »Phagocytic crosstalk between neutrophils and macrophages« investigate how immune cells of the type of phagocytes – in specific neutrophil granulocytes and macrophages – communicate with one another.

Smart Human-in-the-loop Segmentation

Scientist working on the project »Smart Human-in-the-loop Segmentation« aim to develop a powerful deep learning model that is trained with a minimum amount of human effort.

Imaging of Large Tissues

Researchers on the »Imaging of Large Tissues« project are developing a workflow to combine the various microscopy imaging methods and analytical, mass spectroscopy methods.

Cell Tracking in Microscopy Images

The research project »Cell Tracking in Microscopy Images« aims to develop new sophisticated cell detection and tracking algorithms to tackle some of the most challenging tracking problems.