The spindle-assembly checkpoint (SAC) is a safety mechanism which secures accurate chromosome segregation during mitosis.

Promotor: H.S. Overkleeft, J. Neefjes, Co-promotor: M. van der Stelt

The disease acute myeloid leukemia (AML) is characterized by fast progression and low survival rates.

Kinase inhibitors are key therapeutic agents, particularly in oncology, yet their clinical efficacy is often hampered by off-target effects and limited understanding of their cellular target profiles.

The plant hormone auxin plays a central role in the growth and development of plants. Auxin acts in a concentration dependent manner and polar cell-to-cell transport of this hormone determines its distribution in the tissues of plants. This polar auxin transport is mediated by several families of auxin…

This thesis aims to test in vitro pipelines to rapidly and cost-effectively identify molecular mechanisms that drive adverse outcomes in clinical use.

Triple-negative breast cancer (TNBC) is a subtype of breast cancer characterized by limited treatment options and unfavorable clinical outcomes. Therefore, the research described in this thesis focused on the exploration of novel targeted therapies for TNBC.

Monoacylglycerol lipase (MAGL) is the principal enzyme responsible for hydrolysis of the endocannabinoid 2-arachidonoylglycerol (2-AG). MAGL inhibition provides several potential therapeutic opportunities, including anti-nociceptive, anti-inflammatory and anti-cancer activity.

Diacylglycerol lipases (DAGLα and DAGLβ) are responsible for the biosynthesis of the endocannabinoid 2-arachidonoylglycerol (2-AG) in the brain and peripheral tissues. Selective DAGLβ inhibitors have been proposed as a potential treatment for inflammatory diseases with reduced potential for central…

In this thesis an activity-based probe was discovered that could visualize the activity of PLAATs. With an optimized gel-based ABPP assay in hand, screening of a compound library led to the discovery of alpha-ketoamides as a hit for PLAAT3.

The thesis is about how auxin and AGC kinases regulate male fertility. The main AGC kinases studied in this thesis is PDK1, PDK2 and AGC1.5, AGC1.7.

NNMT wordt beschouwd als een nieuw potentieel farmacologisch doelwit in de behandeling van een verscheidenheid van kankers, stofwisselingsziekten en andere pathologieën. Het toenemend aantal publicaties waarin de rol van NNMT bij ziekten wordt opgehelderd, heeft op zijn beurt de ontwikkeling van krachtige…

Large parts of the research described in this Thesis aims at the development of oligopeptide-masked toxins and their in situ immunoproteasome-mediated activation.

Promotor: Prof.dr. P. Hooykaas, Co-promotor: Dr. R. Offringa

The research described in this thesis focused on identifying novel drug targets and synergistic combinations for triple-negative breast cancer (TNBC), a virulent subtype of breast cancer with a dismal prognosis and limited therapeutic options.

This thesis describes the synthesis and biochemical evaluation of a variety of cyclophellitol based activity-based probes and inhibitors targeting various endo- and exo-acting retaining glycosidases. In the last two decades a variety of probes and inhibitors for (hemi)cellulose degrading enzymes have…

The PID-directed shift in PIN polarity has been broadly accepted as one of the essential mechanisms for the regulation of auxin transport polarity.

Pseudomonas Aeruginosa is a Gram-negative bacterium which can form biofilms, increasing its resistance against antibiotics and the host immune system. Polysaccharides are an integral part of this biofilm, one of these polysaccharides is called Psl. PslG is a glycosidase, able to cleave this polysaccharide,…

This thesis describes research aimed at discovering inhibitors selective for either of the two endoplasmic reticulum α-glucosidases, ER-I and ER-II, with the overarching goal of discovering new antiviral agents to treat viruses that rely on host N-glycosylation for proliferation.

Promotor: Prof.dr. H.P. Spaink Co-promotor: Dr. B.E. Snaar

The main focus of the thesis is the discovery and development of novel inhibitors of bacterial metallo-β-lactamases (MBLs).

Less than 1 in 10 drug candidates that enter phase 1 clinical trials actually gets approved for human use.

Glycosidases (GHs) are enzymes responsible for the degradation of carbohydrates and play many roles in human health and pathophysiology. Often, abnormal levels of glycosidase activity are markedly linked to human pathologies.

Supervisor: Anna Vlachodimou

Promotores: Prof.dr. H.S. Overkleeft, Prof.dr. G.A. van der Marel

Plants, are sessile organisms, have developed strategies to adapt to changes in their environment, in part by altering their growth and development.

The clinical potential of applying synthetic lethality to cancer treatment is famously demonstrated by the BRCA1/PARP1 paradigm: a tumor specific defect in BRCA1 – a component of the DNA double-strand break (DSB) repair pathway homologous recombination (HR) – results in a remarkable sensitivity to PARP1…

Glycoside hydrolases (glycosidases/GHs) are widely abundant enzymes in all kingdoms of life and are important biocatalysts that catalyze the hydrolysis of glycosidic linkages in oligo/polysaccharides, glycoproteins and glycolipids with tremendous efficiency

Key publications of the Computational Drug Discovery group

β-Lactamases are enzymes that can break down β-lactam substrates, such as antibiotics, preventing the use of these antibiotics for the treatment of various infectious diseases. However, some compounds, β-lactamase inhibitors, can block these enzymes allowing for possible treatments using a combination…

This thesis focuses on the design and synthesis of activity-based probes and inhibitors targeting enzymes involved in the degradation of specific plant glycans.

Chemical tools to monitor drug-target engagement of endogenously expressed protein kinases are highly desirable for preclinical target validation in drug discovery. Here, we describe a chemical genetics strategy to selectively study target engagement of endogenous kinases.

This Thesis describes the design, synthesis and evaluation as glycoprocessing enzyme inhibitors of focused libraries of iminosugars.

Promotor: H.S. Overkleeft, Co-promotor: M. van der Stelt

Source: J Cheminform, Volume 7, Issue 1 (2015)

This thesis describes the design and development of subunit‐selective inhibitors of particular catalytically active subunits of human constitutive proteasomes and immunoproteasomes.

Glycosidases are essential in fundamental biological processes and are responsible for the degradation of most (oligo)saccharides, glycolipids and glycoproteins.

The current projects of the Molecular Physiology group focus on proteins of the endocannabinoid system, kinases and antibacterial targets. MSc- and BSc-students can contact Jessica van Krimpen-Kraaijenoord to apply for research internships.

The thesis describes the development, synthesis and biological evaluation of several proteasome inhibitor designs. Mainly, this work focusses on designing proteasome inhibitors that selectively inhibit the immunoproteasome, while leaving the constitutive proteasome mostly, if not completely, untouch…

The chemical synthesis of inhibitors and probes targeting endo-glycosidases.

Drug development is a time- and resource-consuming process that starts with the discovery and validation of a (protein) target that contributes to pathogenesis or disease progression.

Bachelor and Master students of all chemistry related studies are more than welcome to take part in our research activities. We have projects on design and synthesis of biologically relevant compounds within an ongoing research project. Supervision, following the apprentice/teacher model, is one of…

Source: PLoS ONE, Volume 10, Issue 3 (2015)

Supervisor: Xue Yang

N-acylethanolamines (NAEs), which include the endocannabinoid anandamide, represent an important family of signaling lipids in the brain. The lack of chemical probes that modulate NAE biosynthesis in living systems hamper the understanding of the biological role of these lipids.

Promotores: H.S. Overkleeft, G.A. van der Marel, Co-Promotor: J.D.C. Codee

Neuraminidases are enzymes that cleave glycosidic linkages of sialic acid. These enzymes are involved in influenza infections as well as in many cellular processes in mammals and micro-organisms.

Triple-negative breast cancer (TNBC) constitutes a small subtype (~15%) of breast cancer, but causes the majority of breast cancer-related deaths.

Chemical biology research at the Leiden Institute of Chemistry is aimed at understanding biological processes at the molecular level to strengthen the knowledge base of human health and disease. The approach to achieve this goal is a fundamental chemical one; with the aid of chemical probes biological…