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Cocaine is a widely abused and addictive drug, resulting in serious medical and social problems in modern society. Currently, there is no FDA-approved medication specific for cocaine abuse treatment. The disastrous medical and social consequences of cocaine abuse have made the development of an anti-cocaine medication a high priority. However, despite decades of efforts, traditional pharmacodynamic approach has failed to yield a truly useful small-molecule drug due to the difficulties inherent in blocking a blocker like cocaine without affecting the normal functions of the transporters or receptors. An alternative approach, i.e. pharmacokinetic approach, is to interfere with the delivery of cocaine to its receptors/transporters and/or accelerate its metabolism in the body. It would be an ideal anti-cocaine medication to accelerate cocaine metabolism producing biologically inactive metabolites. Two natural enzymes may catalyze hydrolysis of cocaine: human butyrylcholinesterase (BChE) and bacterial cocaine esterase (CocE). However, the wild-type enzymes are not suitable as anti-cocaine therapeutics, due to the low catalytic activity, thermoinstability, or short biological half-life. In this investigation, we performed integrated computational-experimental studies to rationally design and discover mutants of these enzymes in order to improve the catalytic activity, thermostability, and/or biological half-life. To rationally design desirable mutants of the enzymes, we have successfully developed computational models, including those for BChE gating, glycosylated BChE structure, BChE-substrate complex structures, BChE dimer/tetramer structures, CocE monomer/dimer structures, and CocE-substrate complex structures. Development of the computational models enabled us to rationally design new amino-acid mutations that may improve the catalytic activity, thermostability, and/or prolonged biological half-life. The computational design was followed by wet experimental tests, including both in vitro and in vivo experiments, leading to discovery of new enzyme forms with not only a high catalytic efficiency against cocaine, but also an improved thermostability and/or prolonged biological half-life. The identified new mutants of BChE and CocE are expected to be valuable candidates for development of a more efficient enzyme therapy for cocaine abuse. The encouraging outcomes of the present study also suggest that the structure-and-mechanism-based design and integrated computational-experimental approach is promising for rational drug design and discovery.

Cocaine is a widely abused drug without an FDA-approved medication. It has been recognized as an ideal anti-cocaine medication to accelerate cocaine metabolism producing biologically inactive metabolites via a route similar to the primary cocaine-metabolizing pathway, i.e. butyrylcholinesterase (BChE)-catalyzed hydrolysis. However, the native BChE has a low catalytic activity against cocaine. We recently designed and discovered a set of BChE mutants with a high catalytic activity specifically for cocaine. An ideal, therapeutically valuable mutant of human BChE should have not only a significantly improved catalytic activity against cocaine, but also certain selectivity for cocaine over neurotransmitter acetylcholine (ACh) such that one would not expect systemic administration of the BChE mutant to interrupt cholinergic transmission. Through integrated computational-experimental studies, several BChE mutants were identified to have not only a considerably improved catalytic efficiency against cocaine, but also the desirable selectivity for cocaine over ACh. Representative BChE mutants have been confirmed to be potent in actual protection of mice from acute toxicity (convulsion and lethality) of a lethal dose of cocaine (180 mg/kg, LD100). Pretreatment with the BChE mutant (i.e. 1 min prior to cocaine administration) dose-dependently protected mice against cocaine-induced convulsions and lethality. The in vivo data reveal the primary factor, i.e. the relative catalytic efficiency, determining the efficacy in practical protection of mice from the acute cocaine toxicity and future direction for further improving the efficacy of the enzyme in the cocaine overdose treatment. For further characterization in animal models, we successfully developed high-efficiency stable cell lines efficiently expressing the BChE mutants by using a lentivirus-based repeated-transduction method. The large-scale protein production enabled us to further characterize the in vivo profiles of the BChE mutant concerning the biological half-life and potency in accelerating cocaine clearance. In particular, it has been demonstrated that the BChE mutant can rapidly metabolize cocaine and completely eliminate cocaine-induced hyperactivity in rodents, implying that the BChE mutant may be developed as a promising therapeutic agent for cocaine abuse treatment.

Cocaine is one of the most reinforcing drugs of abuse and has caused serious medical and social problems. There is no FDA-approved medication specific for cocaine. It is of a high priority to develop an effective therapeutic treatment for cocaine abuse. Human butyrylcholinesterase (BChE) has been recognized as a promising candidate of enzyme therapy to metabolize cocaine into biologically inactive metabolites and prevent it from reaching central nervous system (CNS). However, the catalytic activity of wide-type human BChE against cocaine is not sufficiently high for treatment of cocaine abuse. Dr. Zhan’s lab has successfully designed and discovered a series of high-activity mutants of human BChE specific for cocaine metabolism. This dissertation is mainly focused to address the possible concerns in further development of promising human BChE mutants for cocaine detoxification, including whether the administration of this exogenous enzyme will affect the cholinergic system, whether it can efficiently hydrolyze cocaine’s toxic metabolites, and whether the commonly used therapeutic agents will significantly affect the catalytic activity of the BChE mutants against cocaine when they are co-administered. According to the results obtained, all of the examined BChE mutants have a considerably improved catalytic efficiency against (-)-cocaine, without significantly improving the catalytic efficiency against any of the other examined substrates, including neurotransmitter acetylcholine. Two representative mutants (including E12-7) also have a considerably improved catalytic activity against cocaethylene (formed from combined use of cocaine and alcohol) compared to wild-type BChE, and E12-7 can rapidly metabolize cocaethylene, in addition to cocaine, in rats. Further evaluation of possible drug-drug interactions between E12-7 and some other commonly used therapeutic agents revealed that all of the examined agents, except some tricyclic antidepressants, do not significantly inhibit E12-7. In addition, an effort to discover new mutants with further improved activity against cocaine led to the discovery of a new BChE mutant, denoted as E20-7, according to both the in vitro and in vivo assays. The encouraging outcomes of the present investigation suggest that it is possible to develop a more effective enzyme therapy for cocaine abuse treatment using one of the most promising BChE mutants, such as E12-7 or E20-7.

Soluble guanylyl cyclase (sGC) is the receptor for nitric oxide and a highly sought-after therapeutic target for the management of cardiovascular diseases. New compounds that stimulate sGC show clinical promise, but where these stimulator compounds bind and how they function remains unknown. Here, using a photolyzable diazirine derivative of a novel stimulator compound, IWP-051, and MS analysis, we localized drug binding to the 1 heme domain of sGC proteins from the hawkmoth Manduca sexta and from human. Covalent attachments to the stimulator were also identified in bacterial homologs of the sGC heme domain, referred to as H-NOX domains, including those from Nostoc sp. PCC 7120, Shewanella oneidensis, Shewanella woodyi, and Clostridium botulinum, indicating that the binding site is highly conserved. The identification of photoaffinity-labeled peptides was aided by a signature MS fragmentation pattern of general applicability for unequivocal identification of covalently attached compounds. Using NMR, we also examined stimulator binding to sGC from M. sexta and bacterial H-NOX homologs. These data indicated that stimulators bind to a conserved cleft between two subdomains in the sGC heme domain. L12W/T48W substitutions within the binding pocket resulted in a 9-fold decrease in drug response, suggesting that the bulkier tryptophan residues directly block stimulator binding. The localization of stimulator binding to the sGC heme domain reported here resolves the longstanding question of where stimulators bind and provides a path forward for drug discovery.

京都大学 / 0048 / 新制・課程博士 / 博士(工学) / 甲第19003号 / 工博第4045号 / 新制||工||1622(附属図書館) / 31954 / 京都大学大学院工学研究科分子工学専攻 / (主査)教授 白川 昌宏, 教授 佐藤 啓文, 教授 梶 弘典 / 学位規則第4条第1項該当 / Doctor of Philosophy (Engineering) / Kyoto University / DGAM

Introdução: A associação de uma estatina com ezetimiba é tão eficaz quanto altas doses da mesma estatina na redução do LDL-colesterol. Os efeitos que não dependem dessa redução são chamados de pleiotrópicos, entre os quais podemos citar: melhora da função endotelial, efeitos anti-oxidantes, efeitos anti- inflamatórios, entre outros. Objetivo: comparar a ação de dois esquemas de tratamento que obtêm reduções equivalentes de LDL-colesterol (sinvastatina 80 mg ao dia e associação sinvastatina 10mg/ezetimiba 10 mg ao dia), sobre os efeitos pleiotrópicos: inflamação, função endotelial e oxidação da LDL. Métodos: estudamos 23 pacientes randomizados e na forma de cross-over 2x2. A inflamação foi mensurada através da PCR-us, a função endotelial por meio de ultra-sonografia e a oxidação de LDL pelas dosagens de LDL eletronegativa (LDL-) e do anticorpo anti-LDL-. Resultados: A redução do LDL-colesterol foi similar nos dois grupos (45,27% no grupo sinvastatina/ezetimiba (p<0,001) e 49,05% no grupo sinvastatina (p<0,001), sem diferença entre os tratamentos (p=0,968)). Os dois grupos apresentaram melhora da função endotelial (3,61% no grupo sinvastatina/ezetimiba (p=0,003) e 5,08% no grupo sinvastatina (p<0,001), não houve diferença entre os tratamentos (p=0,291)). Houve melhora nos níveis da PCR-us (redução de -22,8% no grupo sinvastatina/ezetimiba (p=0,004) e de 29,69% no grupo sinvastatina (p=0,01), sem diferenças entre os tratamentos (p=0,380)). Não houve redução significativa da LDL-. Ocorreu aumento na concentração do anticorpo anti-LDL eletronegativa apenas no grupo sinvastatina (p=0,045). Conclusões: as duas formas de tratamento são eficazes na melhora da função endotelial e dos níveis de PCR-us. Somente com o uso da sinvastatina em alta dose houve aumento nos níveis de anticorpos anti-LDL-. / Introduction: The co-administration of a statin with ezetimibe is as effective as high doses of the same statin in the reduction of the LDL-cholesterol. The effects which don´t depend of this reduction are called pleiotropic effects, some among them can be cited: endothelial function improvement, antioxidative and anti-inflammatory effects. Objective: compare the effectiveness of these two different treatments that obtain equivalent reductions of LDLcholesterol (simvastatin 80 mg once a day and co-administration of simvastatin 10 mg once a day and ezetimibe 10 mg once a day), about pleiotropic effects: inflammation, endothelial function and LDL oxidation. Methods: we have studied 23 randomized patients in a 2x2 cross-over study. Inflammation was measured by high-sensitive C reactive protein, endothelial function by echocardiography and LDL oxidation by electronegative LDL and electronegative anti-LDL antibodies levels. Results: the LDL-cholesterol was similar between the two groups (45,27% reduction in the simvastatin/ezetimibe group (p<0,001) and 49,05% reduction in the simvastatin group (p<0,001); no difference between treatments was found (p=0,968). The two groups had improvement in endothelial function (3,61% in the simvastatin/ezetimibe group (p=0,003) and 5,08% in the simvastatin group (p<0,001)), no differences was found between the two groups (p=0,291). High-sensitive C reactive protein had a 22,8% reduction in the simvastatin/ezetimiba group (p=0,004) and 29,69% reduction in the simvastatin group (p=0,01), with no significative difference in any of the two treatments (p=0,380). There was no significative difference in LDL- levels. The anti-LDL- antibodies concentration was increased only in the simvastatin group (p=0,045). Conclusion: the two forms of treatments presented some similar pleiotropic effects - improvement in endothelial function and decreased hs-CRP levels. Only with a high simvastatim dose the anti-LDL- antibodies concentration was increased.

Introdução: A associação de uma estatina com ezetimiba é tão eficaz quanto altas doses da mesma estatina na redução do LDL-colesterol. Os efeitos que não dependem dessa redução são chamados de pleiotrópicos, entre os quais podemos citar: melhora da função endotelial, efeitos anti-oxidantes, efeitos anti- inflamatórios, entre outros. Objetivo: comparar a ação de dois esquemas de tratamento que obtêm reduções equivalentes de LDL-colesterol (sinvastatina 80 mg ao dia e associação sinvastatina 10mg/ezetimiba 10 mg ao dia), sobre os efeitos pleiotrópicos: inflamação, função endotelial e oxidação da LDL. Métodos: estudamos 23 pacientes randomizados e na forma de cross-over 2x2. A inflamação foi mensurada através da PCR-us, a função endotelial por meio de ultra-sonografia e a oxidação de LDL pelas dosagens de LDL eletronegativa (LDL-) e do anticorpo anti-LDL-. Resultados: A redução do LDL-colesterol foi similar nos dois grupos (45,27% no grupo sinvastatina/ezetimiba (p<0,001) e 49,05% no grupo sinvastatina (p<0,001), sem diferença entre os tratamentos (p=0,968)). Os dois grupos apresentaram melhora da função endotelial (3,61% no grupo sinvastatina/ezetimiba (p=0,003) e 5,08% no grupo sinvastatina (p<0,001), não houve diferença entre os tratamentos (p=0,291)). Houve melhora nos níveis da PCR-us (redução de -22,8% no grupo sinvastatina/ezetimiba (p=0,004) e de 29,69% no grupo sinvastatina (p=0,01), sem diferenças entre os tratamentos (p=0,380)). Não houve redução significativa da LDL-. Ocorreu aumento na concentração do anticorpo anti-LDL eletronegativa apenas no grupo sinvastatina (p=0,045). Conclusões: as duas formas de tratamento são eficazes na melhora da função endotelial e dos níveis de PCR-us. Somente com o uso da sinvastatina em alta dose houve aumento nos níveis de anticorpos anti-LDL-. / Introduction: The co-administration of a statin with ezetimibe is as effective as high doses of the same statin in the reduction of the LDL-cholesterol. The effects which don´t depend of this reduction are called pleiotropic effects, some among them can be cited: endothelial function improvement, antioxidative and anti-inflammatory effects. Objective: compare the effectiveness of these two different treatments that obtain equivalent reductions of LDLcholesterol (simvastatin 80 mg once a day and co-administration of simvastatin 10 mg once a day and ezetimibe 10 mg once a day), about pleiotropic effects: inflammation, endothelial function and LDL oxidation. Methods: we have studied 23 randomized patients in a 2x2 cross-over study. Inflammation was measured by high-sensitive C reactive protein, endothelial function by echocardiography and LDL oxidation by electronegative LDL and electronegative anti-LDL antibodies levels. Results: the LDL-cholesterol was similar between the two groups (45,27% reduction in the simvastatin/ezetimibe group (p<0,001) and 49,05% reduction in the simvastatin group (p<0,001); no difference between treatments was found (p=0,968). The two groups had improvement in endothelial function (3,61% in the simvastatin/ezetimibe group (p=0,003) and 5,08% in the simvastatin group (p<0,001)), no differences was found between the two groups (p=0,291). High-sensitive C reactive protein had a 22,8% reduction in the simvastatin/ezetimiba group (p=0,004) and 29,69% reduction in the simvastatin group (p=0,01), with no significative difference in any of the two treatments (p=0,380). There was no significative difference in LDL- levels. The anti-LDL- antibodies concentration was increased only in the simvastatin group (p=0,045). Conclusion: the two forms of treatments presented some similar pleiotropic effects - improvement in endothelial function and decreased hs-CRP levels. Only with a high simvastatim dose the anti-LDL- antibodies concentration was increased.

Charles University Faculty of Pharmacy in Hradec Králové Department of Pharmacology & Toxicology Student: Dominika Bezděková Supervisor: doc. PharmDr. Lukáš Červený, Ph.D. Title of diploma thesis: IN VITRO STUDY OF DRUG-DRUG INTERACTIONS OF HIV PROTEASE INHIBITOR DARUNAVIR ON EFFLUX ABC TRANSPORTERS Abstract: Darunavir is a drug used in the therapy of HIV belonging to the group of protease inhibitors. These protease inhibitors are used as a part of the combination antiretroviral therapy. For the increase of bioavailability, darunavir is always used in combination with ritonavir or cobicistat. As the CYP3A4 and ABCB1 (P-glycoprotein) transporter substrate, darunavir is a drug with a high potential to drug interactions. Considering the amount of adverse effects that can be caused by darunavir, it is necessary to know these drug interactions for the safety of therapy. Inhibition of the intestinal ABCB1 by the co-administrated drugs could also lead to the increased bioavailability of darunavir and to reduction of frequency of administration leading to a cheaper therapy. This thesis studies the drug-drug interactions of darunavir with in vitro methods using two cell lines - MDCKII and Caco-2 cells. The results from the transport of darunavir across the MDCKII cell monolayer indicates that darunavir is a ABCB1...