Promotor: J.G.E.M. Fraaije, Co-Promotor: A. Kros

This work describes the use of click-to-release chemistry to get spatiotemporal control over immunocytokine activity. Until now, immunocytokines (cytokines coupled to a tumor-targeting-moiety) remained active throughout the body, being able to bind their respective receptors, causing mild to severe…

Microscopic insight on lipid-based nanomedicine in vivo remains limited to the perception of the knowledge that could be obtained: if we interpret only what we see, then we only believe to know. Although believing to know encapsulates an undefined amount of uncertainty in the exploration of lipid-based…

The research described in this thesis focused on the use of bioorthogonal antigens to investigate immunological processes in antigen presenting cells. Bioorthogonal antigens are antigenic proteins produced through recombinant expression in a methionine auxotrophic E. coli strain.

Minister Asscher heeft gereageerd op het proefschrift van Marieke Kluin over 'optische regelnaleving - handhaving en regelnaleving in de Nederlandse chemische industrie'.

Bedrijven in de Nederlandse chemische industrie overtreden regelmatig de veiligheidsregels. Dat blijkt uit langlopend onderzoek van wetenschappers van de afdeling Criminologie van de Universiteit Leiden, in samenwerking met de afdeling Criminologie van de Vrije Universiteit Amsterdam. In de afgelopen…

Meer leren over het ontstaan van het leven op Aarde? Dat kan in de Summerschool Crises in Biology.

Een internationaal team van onderzoekers, waaronder chemicus Federico Calle-Vallejo van de Universiteit Leiden, heeft het atoom-schaal-ontwerp van katalysatoren naar een volgend niveau gebracht. Hun onderzoek draagt bij aan de zoektocht naar een methode om energie op een meer efficiënte manier te genereren…

Een van de heilige gralen in het geneesmiddelonderzoek is de veiligheid van chemische stoffen en farmaceutische producten te kunnen beoordelen zonder gebruik van proefdieren. Onderzoekers van onder meer de Universiteit Leiden krijgen daarvoor nu een subsidie van de Nationale Wetenschapsagenda.

Proefdiervrij testen of chemische stoffen schadelijk zijn. Het lijkt een utopie, maar een Europees team gaat een manier ontwikkelen om dit werkelijkheid te maken. Het project RISK-HUNT3R, geleid door Leids hoogleraar Bob van de Water, krijgt hiervoor 23 miljoen euro van de Europese Commissie. Op 1 juni…

Chemici van de universiteit Leiden hebben in samenwerking met de organisatie op het verbod van chemische wapens (OPCW), drie Haagse scholen, de gemeente Den Haag en een van de International Baccalaureate Global Centres een nieuw lespakket ontwikkeld voor het Nederlandse vwo over chemische wapens en…

Is de kwaliteit van het huidige toezicht en handhaving door de overheid dusdanig dat hiermee de bedrijven die met grote hoeveelheden gevaarlijke stoffen werken tot naleving van de wet- en regelgeving worden gebracht?

De bloembollensector wil in 2030 vrij zijn van chemische bestrijdingsmiddelen. Maar volgens wetenschappers gaat de omslag naar biologische teelt niet snel genoeg. In het Leidsch Dagblad vertelt hoogleraar ecotoxicologie Martina Vijver over haar metingen én waarom de situatie haar soms een beetje moedeloos…

Promotor: Prof.dr. H.S. Overkleeft

Bacteria often experience external challenges, such as changes in environmental conditions or attacks by bacteriophages.

Promotor: Prof.dr. M. Ubbink

Freshwater and brackish water ecosystems are arguably the most vulnerable ecosystems on earth, due to concentrated human developments in and around them. The Pontocaspian (PC) region located at the border of Europe and Asia contains a variety of brackish water ecosystems and unique inhabitants, known…

Vitamin A or retinol is essential in embryonic development, the visual cycle and the immune system.

This thesis describes the use of bioorthogonal proteins in immunological settings. It provides an introduction towards the field of protein modification, which was used throughout the thesis for the expression of proteins containing unnatural amino acids.

Cardiovascular diseases (CVDs) are the leading global cause of mortality. Endothelial dysfunction, an early reversible stage of CVD development, is marked by decreased nitric oxide production linked to Ca2+ influx in endothelial cells.

In a typical glycosylation reaction, a donor is activated to form a (variety of) electrophilic species which can react with a nucleophilic acceptor, following a reaction mechanism having both SN1 and SN2 character.

The endocannabinoid receptors CB1R and CB2R are involved in a plethora of processes, and consequently are involved in many pathological conditions. Their wide distribution makes the CBRs both an interesting therapeutic target and hard to study.

Despite the fact that gold nanoparticles (GNPs) are one of the most studied nanoparticles, there is still a necessity for new approaches allowing for effective protective coating to enable wider use of GNPs in biomedical applications.

The lysosomal β-glucosidase named glucocerebrosidase (GCase) is a retaining β-glucosidase that hydrolyzes the glycosphingolipid glucosylceramide (GlcCer) to ceramide and glucose at acid pH.

Phospholipase A/acyltransferase 3 (PLAAT3) and PLAAT4 are enzymes involved in the synthesis of bioactive lipids. Despite sequential and structural similarities, the two enzymes differ in activity and specificity.

Promotor: J.P. Abrahams, Co-promotor: T. Grüne

This thesis describes the use of a combined approach of computational and experimental techniques to gain novel insights to understand the glycosylation reaction and its reactive intermediates.

Every organisms in the tree of life faces the same challenge: the length of its DNA exceeds the volume of the cell it needs to fit in. Several strategies have evolved to solve this problem, one of them being the expression of proteins that bind and organize the DNA.

Schistosomiasis is an acute and chronic disease caused by blood dwelling parasitic trematodes of the genus Schistosoma, and it is classified as the second most socioeconomically devastating parasitic disease, second only to malaria.

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.

Protein–protein complexes are formed via transient states called encounter complexes that greatly influence the formation of the stereospecific complex.

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

Several single-stranded RNA viruses make use of Xrn1-resistant RNAs in their 3’ untranslated regions of their genome RNAs in order to increase their pathogenicity.

Biopolymer sequencing with graphene edge-based tunnel junctions has the potential to overcome current limitations with the third generation of sequencing based on biological nanopores.

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…

Promotor: Prof.dr. J.G.E.M. Fraaije, Co-promotor: A. Kros

Promotor: Jaap Brouwer, Co-promotor: Remus Th. Dame

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

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…

Promotor: A. Kros

Promotor: Prof.dr. M. Ubbink

Promotor: Prof.dr. J.P. Abrahams, Prof.dr. M. van Heel

Membrane fusion is a vital process in living organisms and is mediated by zipper-like proteins.

In this thesis, bioorthogonal chemistry is combined with correlative light-electron microscopy to selectively label and study pathogenic intracellular bacteria within the host immune cell.

Carbohydrates, or sugars, are the most diverse and most abundant biomolecules known. However, the isolation of carbohydrate samples in sufficient amounts and purity is often impractical or even impossible, so the chemical synthesis of glycosides becomes relevant. The glycosylation reaction, in which…

This dissertation presents the synthesis and evaluation of antibody recognition for various capsular polysaccharide (CP) fragments of Staphylococcus aureus (S. aureus).

Supramolecular polymers are class of materials that are formed by non-covalent interactions such as hydrogen bonding, π-π interactions, electrostatic interactions and the hydrophobic effect.

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.

Promotores: Prof.dr. G.A. van der Marel, M. van Heel