Nucleoid associated proteins maintain the architecture of the bacterial chromosome and regulate gene expression, hinting that their role as transcription factors may involve local three-dimensional chromosome re-modelling.

This thesis investigates reactive interfaces in surface science across three domains: heterogeneous catalysis, environmental nanoplastics, and two-dimensional materials.

This thesis focuses on developing wafer-scale two-dimensional (2D) materials by combining synthesis, transfer, characterization, and device integration of graphene, hexagonal boron nitride (h-BN), and BN-doped amorphous carbon.

Climate change is one of the largest challenges faced by humanity. To combat this research into alternatives to fossil fuels is ongoing. Dihydrogen is considered a good alternative fuel, since its burning only forms water.

The growing demand of energy indicates that global energy resources in the form of fossil fuels will not be sufficient in the future. In order to solve potential future energy problems development of a sustainable hydrogen economy is highly desirable.

Solar energy harnessed by plants and algae has great potential to be converted into biofuels for future generations.

Due to their central physiological roles in living organisms, retaining beta-glycosidases have been the subject of tremendous research efforts to examine their structure/function relation using numerous biophysical and biochemical approaches.

With the energy transition toward a renewable energy supply and a CO2-neutral economy, electrification of the energy system is rising in importance, which leads to the challenge of long-term storage of renewable electricity.

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 work describes several studies into the electroreduction of carbon dioxide (CO2RR), both regarding mechanistical aspects and catalyst stability considerations. Mechanistic insights into carbon-carbon bond formation on a silver catalyst are described in Ch 2, were we find an acetaldehyde-like surface…

Catalysis is of extreme relevance in the production of everyday materials and plays a central role in many aspects of our life.

Hydrocarbonylation of alkenes with carboxylic acids in synthesis of carboxylic acid anhydrides is relatively less explored. We herein present a study and optimization of a palladium-catalyzed hydrocarbonylation reaction of alkenes using carboxylic acids as the nucleophile, by which acid anhydrides can…

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.

One of the main challenges in the development of an effective anti-cancer vaccine is the generation of an adequate and directed cellular immune response.

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.

Despite the history of studies on methanol formation from CO2, the dominant elementary reaction steps that constitute the chemical mechanism for this catalyzed process are not determined.

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

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.

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.

The focus throughout this thesis will be on gathering fundamental studies of the detailed structure and composition of the electrode/electrolyte interface effect on the rate and mechanism of key electrocatalytic reactions.

De Faculteit der Wiskunde en Natuurwetenschappen is gevestigd op verschillende locaties in het Bio Science Park Leiden.

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

The redox-conversion reaction of metal-disulfide and metal-thiolate complexes are important, as they may shed light on electron-transfer reactions that often occur in Nature.

Aspergillus niger is an important industrial producer of organic acids and enzymes producing large amounts of spent fungal biomass.

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

Phosphorylation affects all four major biomolecules – proteins, lipids, carbohydrates and nucleic acids – and plays a pivotal role in the most fundamental cellular functions.

Humanity stands at a pivotal juncture, facing the dual challenge of environmental sustainability and rapid population growth, projected to exceed 11 billion by century’s end.

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

This thesis systematically analyzes the physical-chemistry of lipid-graphene interactions with the major objective of reconciliating the variety of results reported in the literature.

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

Bicarbonate buffer is largely found in nature due to its ability to regulate pH variations around neutral values. As the pH changes, so does the speciation of the buffer.

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

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

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.

Lysosomal glycosidases are acid hydrolases that fragment glycoconjugates in lysosomes.

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

Lysosomal acid glucosylceramidase (GBA1) is a lysosomal enzyme that degrades glucolipids with its main substrate being glucosylceramide (GlcCer). Defects in the GBA1 gene lead to glycosphingolipidosis Gaucher disease (GD), in which the hydrolysis of GlcCer is impaired and therefore, it accumulates in…

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.

Inspired by natural photosynthesis, perovskite-based photoelectrochemical (PEC) systems are being developed for artificial photosynthesis, aiming to enhance solar-to-hydrogen conversion for green energy.

In this dissertation iron-based homogeneous catalysts were synthesized, characterized and investigated for water oxidation activity.

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

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.

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

Self-assembly is an abundant process in nature and is vital to many processes in living organisms.

All life on earth contains DNA, which is used to store biological information. Organisms compact their DNA in order for it to fit inside their cell(s).

Electrocatalysis allows for storing electricity or converting it into chemical bonds, producing chemical building blocks and fuels using renewable resources.

Enzymes are innately sensitive to changes in the amino acid sequence, which largely constrains their evolutionary potential, i.e., evolvability. This evolutionary burden can be alleviated in the presence of stabilizing mutations, which increase the buffering capacity of enzymes to tolerate mutations…

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.

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