Abstract
The use and abuse of recreational drugs are on a steady increase in both Europe and the United States. Cocaine addiction and co-administration with other drugs are still a major contributor to the yearly drug-related deaths and overdoses. Currently, there is no therapeutic treatment against cocaine addiction.
The first part of this thesis aimed to understand the atomic basis for cocaine binding to the dopamine transporter (DAT), thought to be responsible for its abuse liability. High-affinity DAT-targeting fluorophores were synthesised, which displayed an “on/off” fluorescence dependent on the amine’s protonation state and bound to DAT in a pH-dependent manner. The compounds were used as an indicator to tell whether cocaine and its analogues bind to DAT via a hydrogen bond or an ionic bond. It was observed that addition of purified protein resulted in a fluorescence increase which could be selectively blocked by addition of a competitive inhibitor, indicating that cocaine and its analogues bind via an ionic interaction.
The second part investigated whether it was possible to incorporate fluorescent moieties directly into the pharmacophore of atypical DAT inhibitors based on modafinil, which are currently explored as a therapeutic treatment against addiction. Several fluorophores were synthesised, and it was found that they retained a high DAT-affinity and -selectivity compared to the serotonin transporter (SERT). Some compounds furthermore showed the propensity to bind to an outward-occluded DAT conformation, suggesting the possibility of them showcasing an atypical behaviour in in vivo experiments.
The third part focused on the psychedelic compound, psilocin, the active metabolite of “magic mushroom” compound, psilocybin. As the clinical use of psychedelic drugs against depression and other diseases related to serotonergic signalling has gained traction in the last years, it was sought to understand psilocin’s interaction with key serotonin modulator, SERT. Psilocin was prepared chemically, after which a CryoEM structure of SERT:psilocin at 2.49 Å resolution was obtained. The structure showcased an interaction between the two, which was corroborated in pharmacological assays and mutational screening. Psilocin thus not only interacts with the serotonin 2A receptors, but also SERT.
The first part of this thesis aimed to understand the atomic basis for cocaine binding to the dopamine transporter (DAT), thought to be responsible for its abuse liability. High-affinity DAT-targeting fluorophores were synthesised, which displayed an “on/off” fluorescence dependent on the amine’s protonation state and bound to DAT in a pH-dependent manner. The compounds were used as an indicator to tell whether cocaine and its analogues bind to DAT via a hydrogen bond or an ionic bond. It was observed that addition of purified protein resulted in a fluorescence increase which could be selectively blocked by addition of a competitive inhibitor, indicating that cocaine and its analogues bind via an ionic interaction.
The second part investigated whether it was possible to incorporate fluorescent moieties directly into the pharmacophore of atypical DAT inhibitors based on modafinil, which are currently explored as a therapeutic treatment against addiction. Several fluorophores were synthesised, and it was found that they retained a high DAT-affinity and -selectivity compared to the serotonin transporter (SERT). Some compounds furthermore showed the propensity to bind to an outward-occluded DAT conformation, suggesting the possibility of them showcasing an atypical behaviour in in vivo experiments.
The third part focused on the psychedelic compound, psilocin, the active metabolite of “magic mushroom” compound, psilocybin. As the clinical use of psychedelic drugs against depression and other diseases related to serotonergic signalling has gained traction in the last years, it was sought to understand psilocin’s interaction with key serotonin modulator, SERT. Psilocin was prepared chemically, after which a CryoEM structure of SERT:psilocin at 2.49 Å resolution was obtained. The structure showcased an interaction between the two, which was corroborated in pharmacological assays and mutational screening. Psilocin thus not only interacts with the serotonin 2A receptors, but also SERT.
| Originalsprog | Engelsk |
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| Forlag | Department of Chemistry, Faculty of Science, University of Copenhagen |
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| Antal sider | 411 |
| Status | Udgivet - 2024 |