The aim of the research presented in this thesis was to develop new methods forchallenging systems in liquid-state NMR using paramagnetic effects generated by thetwo-armed probe CLaNP-5.

Ice, the solid state of water, plays an important role on our planet as well as the entire universe.Despite the fact that an individual water molecule has a very simple structure, its chemical bonding in the solid phase can be surprisingly complex.

Zebrafish is an excellent model organism for studying various human diseases. Due to opaqueness of the adult phase, in vivo studies are restricted to early embryonic stages. This raises the need for rapid sensitive and non-invasive in vivo imaging methods to follow developmental processes, not only…

Human civilization consumes a huge amount of fossil fuels, which has resulted in an atmospheric CO2 level which has not been higher in over 800 millennia.

Promotor: Prof.dr. M. Ubbink

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.

Global healthcare is on the verge of an antibiotic availability crisis as bacteria have evolved resistance to nearly all known antibacterials. Identifying new antibiotics that operate via novel modes-of-action is therefore of high priority.

The main subject of this thesis is the design and synthesis of paramagnetic molecules for protein studies with NMR and EPR spectroscopy.

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.

Bet v1, the major allergen in birch pollen, is one of the main causes of allergies such as asthma and rhino-conjunctivitis. Additionally it is the main cause of birch pollen allergy in humans.

Cambridge University Press has published a new book co-authored by researchers from Leiden University, offering both an introduction to machine learning and deep neural networks, and an overview of their applications in quantum physics and chemistry — from reinforcement learning for controlling quantum…

This thesis describes the development and optimization of the first molecular tools to study the enzyme PLA2G4E.

Promotor: J.P. Abrahams, Co-Promotor: N.S. Pannu

Leiden University has developed a radically different method for large scale production of diverse nanoparticles and their alloys.

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.

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.

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

This thesis describes the structural and biochemical characterization of the β-lactamase BlaC from Mycobacterium tuberculosis (Mtb), and the Alr and YlmE proteins from Streptomyces coelicolor A3(2).Mtb is the main cause of tuberculosis.

In this thesis I highlight the applications of Oxford Nanopore Technologies (ONT) sequencing. This technique is a relatively new approach in the sequencing field, where nanopores are embedded in a membrane, DNA molecules are pulled through nanopores and an electrical current serving as the sequencing…

Marc Koper’s research focuses on electrocatalysis and electrochemical surface science for sustainable energy and chemistry. Reactions of interest are the redox reactions of the oxygen/hydrogen cycle (water oxidation, hydrogen evolution), the carbon cycle (reduction of carbon dioxide, oxidation of small…

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 Graduate School of Science offers PhD programmes spanning the entire spectrum of science from Mathematics to Environmental Science.

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

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…

.

The research aims to explore the evolutionary adaptability of enzymes and the impact of temperature on protein evolution pathways, using M. tuberculosis β-lactamase BlaC as the object of study. Enzymes inherently embody a delicate balance between activity and stability, and the acquisition of new enzymatic…

Due to the modern techniques of combinatorial chemistry and high-throughput screening, data on the biological activity of many millions of compounds is known. However, it is still very difficult to transfer this data into knowledge: if we know that compounds A and B bind to a certain protein with high…

Dr. at the Department of organic chemistry, Wageningen University - the Nederlands

The studies presented in the work show the potential of the integrative use of biophysical data in defining the structural basis of protein interactions.

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…

A key step in the synthesis of oligosaccharides and glycoconjugates is the formation of the glycosidic bond.

This dissertation explores new chemical strategies for the synthesis of self-adjuvanting peptide conjugates and immunomodulatory ligands aimed at targeted activation of the immune system.

Promotor: M. Ubbink, Co-promotor: G. Siegal

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

In this thesis unconventional tools based on fluidic interfaces were developed to study the surface and interfacial chemistry of graphene, to characterize the intrinsic properties of graphene, to disentangle the effects of substrate and of the environmental factors, and to improve handling protocols…

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.

Neurodegenerative diseases pose a large medical and societal challenge. The etiology of these diseases is still poorly understood, which makes drug discovery for these diseases difficult.

Lecture

This thesis investigates catalytic reactions at the atomic scale using scanning tunneling microscopy (STM), with a focus on Fischer–Tropsch synthesis, a key industrial process that converts hydrogen and carbon monoxide into liquid fuels.

In June the Final Festival took place, the closing event of the 'Social Science Lab'. New participants of Honours College Science and Society presented their solution for a current social problem.

Compare human social behaviour at a country level and you will find differences. Japan has the highest score whereas the Netherlands is just above average. This is what psychologist Niels van Doesem discovered in research with an international team of 64 colleagues in 31 industrialised countries. Their…

This thesis describes the evaluation of novel natural products with antibacterial activity enabled by total chemical synthesis.

Division contact information & address

The drug BIA 10-2474 inhibits fatty acid amide hydrolase (FAAH), a lipase that degrades a specific endocannabinoid. On the basis of this activity, BIA 10-2474 was being developed as a potential treatment for anxiety and pain. In a phase 1 trial of the drug, one subject died, and four others suffered…

A high-end label: Cyclophellitol aziridine-type activity-based probes allow for ultra-sensitive visualization of mammalian β-glucosidases (GBA1, GBA2, GBA3, and LPH) as well as several non-mammalian β-glucosidases (see picture). These probes offer new ways to study β-exoglucosidases, and configurational…

Three at the same time: a ligation strategy combining tetrazine–norbornene cycloaddition, Staudinger–Bertozzi ligation, and copper(I)-catalyzed click reaction was used to label the three catalytic activities of the proteasome simultaneously in a single experiment. The orthogonality of the three ligation…

A 5 million euros grant from the Dutch Research Agenda allows Anouk de Koning and co-applicants Femke Kaulingfreks and Maartje van der Woude to study social interventions in eight Dutch cities in an innovative and interdisciplinary way.

Siemens recently took over the Leiden software company Culgi, founded by professor and inventor J.G.E.M. (Hans) Fraaije. We spoke to him about the algorithm that made him successful, the role of a university in our society and his ambitions at Siemens. ‘I was looking for Siemens, and they were looking…

What interests and motives shape how people cooperate, clash and place their trust in one another? For more than 36 years, Van Dijk explored these questions using experimental games in the laboratory. 'Games strip complex issues back to their core.'