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

The ongoing increase in antimicrobial resistance combined with the low discovery of novel antibiotics is a serious threat to our health care.

The Chemical Probe Facility is part of the Leiden Early Drug Discovery & Development (LED3) center. Activity-based protein profiling (ABPP) is one of the pillars of chemical biology. ABPP determines the activity of entire protein families in living cells and tissues under physiological conditions, such…

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…

To address biological questions related to human health, chemical tools are essential. Covalent or non-covalent interactions of compounds with biomolecules offer a range of possibilities for study. They can be used to identify enzymes based on their activity, to influence cellular regulation, by changing…

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.

The LED3 Network, consisting of researchers from the Leiden Institute of Chemistry (LIC), the Institute of Biology Leiden (IBL) and the Leiden Academic Centre for Drug Research (LACDR), is very excited to organise the “LED3 Chemical Biology Talks”. This lecture series brings excellent researchers in…

Overkleeft

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…

Synthesis and application of chemical biology tools to study immunomodulatory signaling lipids.

The cannabinoid receptor type 2 (CB2R) is associated with several inflammatory diseases with an unmet medical need (e.g. Alzheimers, multiple sclerosis, reumatoid arthritis). Development of new chemical biology strategies to study this protein is essential to aid future development of drugs for these…

Chemical-induced organ toxicity is a major concern in the development and use of chemicals, including drugs, pesticides, industrial chemicals and cosmetics. In the last decades, the onset and progression of chemical-induced organ toxicity has been linked amongst others to perturbation of mitochondri…

At the moment, over 350.000 chemicals are registered worldwide for production and use. Their application, however, may harm human health and the environment.

The inverse electron demand Diels-Alder (IEDDA) pyridazine elimination emerged in 2013 as a new bioorthogonal reaction and constitutes a prime example of what is now known as dissociative bioorthogonal chemistry. The research described in this Thesis aims to develop synthetic strategies which enable…

In this thesis, the discovery and optimization is described of chemical tools to study the N-acylethanolamine (NAE) biosynthetic pathway.

This thesis has described novel synthetic methods to produce a variety of (glyco)peptides and their application in the study of various immunological processes.

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

Polycyclic aromatic hydrocarbons (PAHs) are the most abundant class of organic compounds in space. The PAH field evolves from the constant interaction between experimentalists, theorists, modellers and observers. While laboratory research and quantum chemical calculations together set up the molecular…

This thesis addresses the chemical processes that determine the compositions of giant planet atmospheres.

How and why latex bearing plants select specific chemical compounds for eco-chemical interactions with its biotic factors?

Overkleeft

Promotor: A.P.IJzerman Co-promotor: A. Bender

Can cyclic peptides provide a new generation of antibiotics?

This perspective addresses four challenges facing theorists whose aim is to make quantitatively accurate predictions for reactions of molecules on metal surfaces, and suggests ways of meeting these challenges, focusing on dissociative chemisorption reactions of H2, N2, and CH4.

This research studies the future perspectives for Malaysian space law. It aims at demonstrating the development of Malaysian outer space activities inclusive of her status with respect to United Nations space conventions and her membership of international and regional space-related organizations.

This thesis mainly extends the theory of positive operators on Riesz spaces to a setting of pre-Riesz spaces.

Over several decades, a variety of computational methods for drug discovery have been proposed and applied in practice. With the accumulation of data and the development of machine learning methods, computational drug design methods have gradually shifted to a new paradigm, i.e. deep learning methods…

Promotores: H.S. Overkleeft; G.A. van der Marel Co-Promotor: B.I. Florea

MHC class I and MHC class II molecules present peptides to the immune system to drive proper T cell responses. Pharmacological modulation of T-cell responses can offer treatment options for a range of immune-related diseases.

We review the state-of-the-art in the theory of dissociative chemisorption (DC) of small gas phase molecules on metal surfaces, which is important to modeling heterogeneous catalysis for practical reasons, and for achieving an understanding of the wealth of experimental information that exists for this…

Advanced sensing techniques require graphene with high quality and well-controlled surface chemistry.

The ACPA Exhibition Space is located at the basement of the P.J.Veth building. This new space is conceived as a platform for the exhibition of work developed by researchers affiliated with the Academy of Creative and Performing Arts (ACPA).

Promotor: A. Doelman, Co-promotor: M.F.E. de Jeu

In what way can new tools and techniques be used to develop drug candidates for the treatment of neurological disorders?

PhD defence

Sphingolipids are important membrane compounds with a variety of functions. In mammalian cells, different enzymes are involved in the metabolism of sphingolipids, but interruption of this metabolism process leads to different diseases.

The work described in this Thesis is focused on the assembly of oligosaccharide fragments derived from a fungal polysaccharide, galactosaminogalactan (GAG) and fragments of the exopolysaccharide Pel, generated by Pseudomonas aeruginosa.

Plants produce an astonishing variety of secondary metabolites (SMs) which are thought to play vital roles in the fitness of plants through ecological interactions.

Conference

This thesis describes the design and synthesis of fragments of various cell wall carbohydrates of the Streptococcus species, including the branched Group B-specific antigen (GBC) of Group B Streptococcus, glycerol phosphate (GroP) modified group A carbohydrate (GAC), and the O-acetylated type 1 capsular…

This thesis describes the synthesis and biological evaluation of TLR2/6, TLR4, TLR7/8 and TLR9 ligands, of which the activity can be conditionally controlled.

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

Promotor: S.M. Verduyn Lunel, Co-promotor: S.C. Hille

Is it possible for sugar patterns on cells to activate the immune system to combat cancer?

This paper describes two synthetic lipid models designed to replace human stratum corneum (SC) in studies of the impact of volatile organic chemicals on the molecular organization of the skin barrier lipids.

Walsh

Can you imagine a radically different world? In our times dominated by neoliberal capitalism, we seem to lack not only viable alternatives, but also the capacity to envision anything outside of the status quo.

Promotor: Prof.dr. R. Verpoorte, Co-promotores: Dr. Y.H.Choi, N.R. Mustafa

Promotor: E. F. van Dishoeck, Co-promotor: C. Walsh

Cellular stress response pathways are activated upon exposure to chemicals and help organisms deal with various molecular dangers (e.g. oxidative stress). When these pathways become hyper-activated an adverse response takes place and cells die, which may lead to organism-level toxicity such as drug-induced…