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TARGETING PROTEASOME IN BABESIA PARASITES TO COMBAT HUMAN BABESIOSISTemitope S Aderanti (18423210) 23 April 2024 (has links)
<p dir="ltr">Human babesiosis is a malaria-like, tick-borne infectious disease of major public health importance with a global distribution. Babesiosis is caused by intraerythrocytic, apicomplexan parasites of the genus Babesia. In the United States, human babesiosis is primarily caused by Babesia microti and Babesia duncani. Of these parasites, B. duncani infection is lethal to susceptible patients. Current treatment for babesiosis includes either the synergistic use of atovaquone and azithromycin or the combination of clindamycin and quinine. However, the side effects and the resistance posed by these parasites called for alternative approaches for the treatment of human babesiosis. Parasite-derived proteases play several functions in the context of parasitic lifestyle and regulate basic biological processes including cell death, cell progression and cell migration. We hypothesized that proteases are promising class of drug targets in Babesia parasites. Using the SYBR-Green assay, we screened a protease inhibitor library consists of 160 compounds against B. duncani in vitro culture at 50µM and identified 13 preliminary hits. Additionally, dose response assays of hit compounds against <i>B. duncani</i> and <i>B. microti</i> in vitro cultures identified 5 compounds as effective inhibitors against parasite growth. Of these 5 compounds, we chose ixazomib, a proteasome inhibitor as a potential drug for further studies based on its lower IC50 of 58nM as well as a higher therapeutic index as compared to other hit compounds. We demonstrated that in a mouse model infected with <i>target,</i>, the most effective inhibitor, the prodrug of ixazomib at a low dose of 2.5mg/kg lowers parasite proliferation without causing any adverse effects in animals. Thus, our studies suggest that Babesia proteasome may be an important drug target, and ixazomib may be a potential compound that may be used for the treatment of human babesiosis.</p>
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Moderatoreffekte bewusster und unbewusster Faktoren auf implizite und explizite Motive sowie die MotivkongruenzMempel, Gordon 16 December 2013 (has links)
Im Rahmen zweier Studien im Leistungssport werden die Effekte bewusster und unbewusster Faktoren auf implizite und explizite Motive untersucht. Es kann die Distinktheit der Vorhersagebereiche impliziter und expliziter Motivdiagnostik repliziert werden. Dabei wird aufgezeigt, dass die handlungsführenden Effekte impliziter und expliziter Motive jeweils exklusiv durch unbewusste Impulskontrolle und bewusste Selbststeuerungskompetenzen moderiert werden. Allein implizite Prozesse (implizite Motive, Impulskontrolle) besitzen prognostischen Wert für sportliches Leisten in Situationen die unbewusst verarbeitet werden. Explizite Prozesse (explizite Motive, bewusste Selbststeuerung) hingegen sagen sportliches Leisten in bewusst verarbeiteten Situationen des sportlichen Wettkampfs vorher. Die differentielle Prognostizität direkter und indirekter Motivdiagnostik in der Sportpsychologie kann durch die Berücksichtigung adäquater Faktoren verbessert werden. Aufgrund der Ergebnisse dieser Arbeit ist bei der Auswahl adäquater Persönlichkeitsvariablen darauf zu achten, dass das zu prognostizierende Kriterium und die Erhebungsmethodik bezüglich ihres Grades an bewusster Bearbeitung miteinander übereinstimmen. / The effects of conscious and unconscious factors on implicit and explicit motives were examined in the context of two studies. The distinct array of prediction by implicit and explicit motive diagnostic can be replicated. Though it was possible to provide evidence for the exclusive moderation of implicit motives by unconscious activity inhibition while explicit motives were moderated by conscious skills of self-regulation. Only the implicit processes (implicit motives and activity inhibition) proof a value to predicting human activity in situations coped without consciousness. In contrast only explicit processes (explicit motives and conscious skills of self-regulation) can predict the outcome of behaviour in situations coped with consciousness. The results of that paper can improve the differential prediction of direct and indirect motive diagnostic by regarding the adequate moderator factors. Further investigations will have the ability to improve the value of motivational predictors if they consider, that the level of consciousness is consistent within the situation of ascertainment the motivational predictor and the situation the criteria is imposed.
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Planejamento baseado na estrutura da metaloprotease BPMP-I e avalia??o de tiossemicarbazonas ativas contra a pe?onha da serpente Bothrops pauloensis / Structure-based planning Of BPMP-I metalloprotease and evaluation Of thiosemicarbazones active against The snake venom Bothrops PauloensisFerreira, Francis Barbosa 04 August 2016 (has links)
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Previous issue date: 2016-08-04 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior - CAPES / In this work, semi and thiosemicarbazones selected from the LaDMol-QM library, were used
to study their interactions with a metalloproteinase from the snake Bothrops pauloensis
(BpMP-I) by molecular modelling and enzymatic inhibition assays with the toxin. The
crystalographic structure of BaPI (PDB code: 2W12) was used as a mold to build the 3D
model of BpMP-I by homology modeling. The theorical model of BpMP-I showed good
quality parameters and was used in a subsequent molecular modeling study. The
thiossemicarbazones showed better molecular docking results and in vitro enzymatic
inhibitions assays than semicarbazones. Studies by semi-empirical methods indicate a positive
enthalpy of interaction, suggesting that the enzyme inhibition by these compounds must be a
entropy-driven process. The results were used together to select the LDQM-IN-23 compound
and propose rationally designed modifications to improve the interactions with the toxin. The
study of the catalytic site of BpMP-I showed that there is an adjacent pocket with amino
groups of the peptide bonds available for interaction. All results were used together to design
structural changes, aiming the enhancing of the interaction with toxin. Therefore, was
proposed the insertion of the carboxyl group with different spacers, containing 2 (LDQM-IN-
23b) and 3 methylene groups (LDQM-IN-23c). The docking results and semi-empiric
optimization showed that there was a considerable improvement in the interaction for the
modified compounds. The modified compounds were synthesized and tested for biological
and enzymatic inhibition activity. It was observed that the IC50 values have improved: the
original molecule, LDQM-IN-23 has an IC50 of 3,011 ?M and the modified molecules have
IC50 of 79.12 (LDQM-IN-23b) and 1.77 ?M (LDQM-IN-23c). These molecules were tested
for inhibition of hemorrhagic activity induced by Bothropoidin, a P-III class
metalloproteinase, and by the B. pauloensis whole snake venom. The three molecules can
inhibit the hemorrhagic activity induced by isolated toxin and whole venom, and LDQM-IN-
23c showed higher efficiency compared with the other two, and in a rate of 1:10 (w/w
venom/inhibitor) the inhibition of the hemorrhagic activity was 100%. A molecular docking
study of this lead compound with Snake Venom Metalloproteases (SVMPs) from different
snake species and genera showed that this molecule can effectivelly interact with these
SVMPs. / Neste trabalho, foram utilizadas semi e tiossemicarbazonas, selecionadas na quimioteca do
LaDMol-QM (Dequim-UFRRJ), para o estudo das intera??es destas com o s?tio ativo de uma
metaloprotease da pe?onha da serpente Bothrops pauloensis por modelagem molecular e
ensaios de inibi??o da atividade enzim?tica e biol?gica sobre a toxina. A estrutura
cristalogr?fica de uma metaloprotease (BaPI) complexada com um inibidor (um
peptideomim?tico) (c?digo PDB 2W12) foi utilizada como molde para a constru??o do
modelo 3D da metaloprotease da pe?onha de B. pauloensis (BpMP-I). O modelo 3D te?rico
da BpMP-I, in?dito para esta toxina, apresentou bons par?metros de qualidade, sendo
considerado adequado para estudos de planejamento de ligantes baseado na estrutura. As
tiossemicarbazonas obtiveram melhores resultados, quando comparados com os resultados
das semicarbazonas, tanto para os ensaios de docagem molecular quanto para estudos de
inibi??o da atividade enzim?tica in vitro. Estudos por m?todos semiemp?ricos indicam uma
entalpia de intera??o positiva, sugerindo que a inibi??o enzim?tica por estes compostos deve
ser um processo controlado entropicamente. Os resultados foram utilizados para selecionar o
derivado LDQM-IN-23 e propor modifica??es estruturais planejadas racionalmente, visando
melhorar a intera??o deste com a toxina. O estudo do s?tio catal?tico da metaloprotease
mostrou que esta possui uma cavidade adjacente com grupos amino das liga??es pept?dicas
dispon?veis para intera??o. Foi proposta, ent?o, a inser??o de um grupo carboxilato com
diferentes espa?adores, 2 (LDQM-IN-23b) e 3 grupos metileno (LDQM-IN-23c). Os
resultados de docagem e otimiza??o semi-emp?rica mostraram que houve uma melhora
consider?vel na intera??o dos ligantes modificados, os quais foram sintetizados e testados
para as atividades de inibi??o enzim?tica e biol?gica. Na inibi??o enzim?tica, houve melhora
da CI50 com o aumento do espa?ador. O composto LDQM-IN-23 tem CI50 de 3011,00 ?M e
os compostos modificados possuem a CI50 de 79,12 (LDQM-IN-23b) e 1,77 ?M (LDQM-IN-
23c). Estes compostos foram testados para a inibi??o da atividade hemorr?gica in vivo
induzida pela Botropoidina, uma metaloprotease da classe P-III, e pela pe?onha bruta de B.
pauloensis. Os tr?s compostos conseguiram inibir a atividade hemorr?gica induzida pela
toxina isolada e pela pe?onha, sendo que o composto LDQM-IN-23c mostrou maior
efici?ncia, quando comparado com os outros dois, e para a propor??o de 1:10 (m/m
pe?onha/inibidor) a inibi??o da atividade foi de 100%. Foi realizado um estudo de docagem
deste composto l?der com outras metaloproteases de pe?onha de serpentes (SVMPs ? Snake
Venom Metalloproteinases), de esp?cies e g?neros diferentes, mostrando que este ligante
consegue interagir com outras SVMPs e ? um candidato para inibir a atividade hemorr?gica
de SVMPs presentes na pe?onha, n?o s? de B. pauloensis, mas de outras serpentes
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