Programa de Pós-Graduação em Química Medicinal e Modelagem Molecular - PPGQMMM/ICS

URI Permanente desta comunidadehttps://repositorio.ufpa.br/handle/2011/14430

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Acesso aberto (Open Access)
Estudo do mecanismo conformacional da proteína 3-hidroxi-3- metilglutaril Coenzima A Redutase (HMGR) com as estatinas e substrato através de Dinâmica Molecular, PCA e Energia Livre
(Universidade Federal do Pará, 2017-08-03) COSTA, Clauber Henrique Souza da; SILVA, Jerônimo Lameira; http://lattes.cnpq.br/7711489635465954; https://orcid.org/0000-0001-7270-1517
Cholesterol is a substance of paramount importance for all animals. However, its high level in the human body is linked to the two major diseases that kill the world: ischemic heart disease and stroke. One of the synthetic drugs used in the treatment of hypercholesterolemia are statins, inhibitors of 3-hydroxy-3-methylglutaryl Cozyme A reductase (HMGR), which act primarily on the liver by inhibiting a conversion of the HMG-CoA substrate into mevalonic acid, which is the metabolite Cholesterol precursor. Studies Molecular Dynamics (MD) combined with Principal Component Analysis (PCA) were performed to verify the mechanism of the changes in the Cterminal Flap domain form (residues His861, Leu862, Val863, Lys864, Ser865 and Hys866) after binding substrate and efficient statins in inhibiting the HMGR enzyme. A total of 500 ns of MD simulation time were performed in this study. Binding Free Energies calculations were used, which estimate that the structural mechanism of the Flap is related to an action of the HMGR protein, since domain control or access to the active site of the enzyme. The results also show that the structural modification of Flap increases the energy contribution of the system by involving larger interactions with catalytic residues and, consequently, an ability to inhibit cholesterol production, as observed for the catalytic His866, which has a very favorable contribution when the Flap is in the closed state, with energy of -14,802 Kcal/mol, and when the Flap passes to the open state the contribution is less favorable, with -1,022 Kcal/mol, for 1 inhibitor, showing that in the closed state the catalytic residue is directly involved and contributes in a favorable way to the system, leading to a better understanding of the conformational changes of HMGR after a binding of statin derivatives and HMG-CoA substrate.
Acesso aberto (Open Access)
Estudo teórico da reação de metilação da proteína lisina metiltransferase (pkmt)
(Universidade Federal do Pará, 2019-10-09) GOMES, Guelber Cardoso; LIMA, Anderson Henrique Lima e; http://lattes.cnpq.br/2589872959709848; https://orcid.org/0000-0002-8451-9912; SILVA, Jerônimo Lameira; http://lattes.cnpq.br/7711489635465954; https://orcid.org/0000-0001-7270-1517
Cancer is one of the main targets in academic research and its understanding is related to gene regulation through histone methylation. G9a protein is responsible for the methylation of histone 3 Lysine 9 (H3K9), which can perform one or two methylations on this specific residue. Thus, computational techniques were used to describe this reaction through QM/MM simulation using the techniques of SEP, PMF in the Dynamo program and the mechanism in the AMBER program with the methods AM1, AM1D, PM3, PM6 and RM1 determining the best method. the parameters to describe the reaction. The results show that the reaction for deprotonation of Lysine 9 showed better values in the Amber18 program, being close to expected through a direct transfer of Lysine 9 to Tyrosine 1154 with the RM1 method and energy barrier of 27.15 kJ/mol. The transfer of the methyl group from the SAM molecule to Lysine 9 showed that the PM6 method using the Dynamo PMF technique had an energy barrier of 72.80 kJ/mol which is close to that obtained by the experimental data.
Acesso aberto (Open Access)
Simulação computacional do mecanismo catalítico da enzima catecol o-metiltransferase
(Universidade Federal do Pará, 2017-02-16) SILVA, Edson Leandro de Araújo; SILVA, Jerônimo Lameira; http://lattes.cnpq.br/7711489635465954; https://orcid.org/ 0000-0001-7270-1517
Methyl transfer reactions are very important in biological systems, the enzyme catechol O-methyltranferase catalyzes a transfer reaction of a methyl group of the co-substrate S-adenosylmethionine to dopamine. This disease is related to a Parkinson's disease that is a neurodegenerative disease that affects 7 to 10 million people of the world population, mainly a parcel over 60 years. Due to the importance of the reaction catalyzed by this enzyme, computational tools in conjunction with quantum mechanics methods were used to study the mechanism of reaction of the methyl transfer of S-adenosylmethionine to dopamine. In this study, the presence or not of Mg2+ in the reaction and changes in dopamine structure for catechol and phenol were taken into account in order to propose a quantum region more suitable for future non-enzymatic simulation work. The methods used in the PM6 semi-present method, the ab initio DFT and the MP2 correlation. The methods used include PM6 semiempirical method, ab initio DFT and perturbation MP2, where the first method was highlighted in the description of all reactions studied. The reaction with the catechol in the solvent had the following values of energy barriers: 18.62 kcal/mol (PM6); 9.91 kcal/mol (DFT); 14.44 kcal/mol (MP2). The presence of the Mg2+ ion in the same reaction with the catechol showed the following energy barrier values: 24.55 kcal/mol (PM6); 15.99 kcal/mol (DFT); 17.39 kcal/mol (MP2). The PCM solvation model was used to study a reference reaction in the enzymatic system and to analyze how energy barriers of the reaction in water and with barriers obtained in the gas.

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