Drug candidates with a covalent binding mode have gained interest since the approval of multiple covalent anticancer drugs, but were long avoided due to concerns regarding promiscuous reactivity... Show moreDrug candidates with a covalent binding mode have gained interest since the approval of multiple covalent anticancer drugs, but were long avoided due to concerns regarding promiscuous reactivity with off-target proteins. In this dissertation, the scope and versatility of the newly discovered in situ thiol–alkyne reaction is evaluated: the nonactivated alkynes exhibit an unprecedented target reactivity with excellent thiol selectivity, thus potentially outperforming currently used cysteine-reactive warheads. Chapter 1 starts with the history of (ir)reversible covalent inhibition, the reactivity of (non)activated alkynes, and the serendipitous discovery of the thiol–alkyne reaction. Established technologies for direct detection of covalent protein–drug adducts are reviewed in Chapter 2, and in Chapter 3 a detailed guide for the evaluation of (ir)reversible covalent inhibitors to obtain relevant kinetic parameters is provided, accompanied by kinetic simulations and step-wise protocols for enzymatic activity assays. In Chapter 4, the nitrile warhead in reversible CatK inhibitor odanacatib (ODN) is replaced with alkyne warheads to investigate whether it an irreversible covalent adduct is formed with cysteine protease cathepsin K (CatK) despite having a small recognition element. In Chapter 5, we evaluate if nonactivated alkynes can target noncatalytic cysteine residues by replacing the irreversible covalent acrylamide warhead in EGFR/HER2 inhibitor neratinib by an alkyne warhead. In Chapter 6, the impact of substituents on the alkyne warhead is explored using a panel of ubiquitin-based ABPs bearing substituents on the propargylamide warhead. Finally, the most important findings are summarized in Chapter 7, and placed in the context of covalent drug discovery. Show less
Stress, obesity and (stress-related) mood disorders such as depression and anxiety disorders are highly prevalent in modern society. These diseases often coincide. This may be because they trigger... Show moreStress, obesity and (stress-related) mood disorders such as depression and anxiety disorders are highly prevalent in modern society. These diseases often coincide. This may be because they trigger and reinforce each other, creating a vicious cycle. Social and psychological factors play a role in this cycle, but in this thesis we focused on the underlying biological mechanisms. We identified new obesity-related factors that likely affect fear and discovered new sites of action in the brain for factors that are already known to regulate fear. We also applied three novel drug treatment strategies. Each of these target (different) components of the stress system and were shown to alleviate stress- or diet-induced metabolic disease in mice. Certain strategies reduced obesity, while others seemed to prevent or even cure fatty liver disease in mice. This thesis thus represents a step towards breaking the vicious cycle between stress, obesity and (stress-related) mood disorders. Show less
