Estudio in-silico de interacción molecular de la benzoilmetilecgonina frente a las enzimas BChE y CocE

Abstract

Así mismo, se analizó la variación presentada en la distancia entre los carbonos alfa de los aminoácidos involucrados en la mutación peptídica y su relación con la estabilidad enzimática. Este estudio preliminar de interacciones ligando-proteína contribuye al entendimiento de las interacciones intermoleculares que hacen a la CocE una enzima que pueda ser usada en la terapéutica para el tratamiento en la intoxicación por cocaína. Los resultados obtenidos en el presente estudio muestran las energías de acoplamiento de la benzoilmetilecgonina con las enzimas nativas y mutada; -8,6 kcal/mol en BChE, -6,8 kcal/mol en CocE nativa, -7,2 kcal/mol en CocE mutante. Los estudios de dinámica molecular muestran que el movimiento promedio (RMSD) de la benzoilmetilecgonina en el sitio de unión de las enzimas es mayor en el complejo; con BChE; (4,5 Å), seguido por nativa CocE nativa (3,4 Å), siendo menor y más estable en CocE mutante (3,0 Å). Finalmente, el estudio permite concluir que el reemplazo de los aminoácidos Leu196 e Ile301 por cisteínas, se evidencia que la CocE mutante presenta un menor movimiento durante la dinámica molecular respecto a la CocE nativa, ello indicaría que probablemente las mutaciones aumentan la estabilidad enzimática a 37 °C.

The importance of finding ways to reduce cocaine consumption, addiction and intoxication has led to the study of how to induce a decrease in cocaine plasma levels through accelerated catalytic degradation mechanisms with the help of human and bacterial enzymes. Using computational tools, it can help to understand the molecular interaction between the benzoylmethylecgonine ligand and the BChE and CocE enzymes. In the present investigation, a computational study was carried out, where the different behaviors of benzoylmethylecgonine (cocaine) against native and mutant butyrylcholinesterase (BChE) and cocaine esterase (CocE) enzymes were analyzed, by means of molecular docking. The study allowed to identify the most probable binding, the docking energies and the interactions with the binding residues. In turn, the tertiary structure of the enzymes was studied, where the native structures were evidenced and differentiated from the mutated ones. On the other hand, the behavior of the ligand-protein complex, mean square deviation of atomic positions, mean square fluctuation, molecular movement and contacts through a simulation time of 40 nanoseconds (ns) were studied using molecular dynamics. It was possible to evaluate the behavior of the dimer of the native and mutated bacterial enzymes of the species Erythroxylum coca (25 °C) at room temperature and human body temperature (37 °C). Likewise, the variation presented in the distance between the alpha carbons of the amino acids involved in the peptide mutation and its relationship with enzymatic stability was analyzed. This preliminary study of ligand-protein interactions contributes to the understanding of the intermolecular interactions that make CocE an enzyme that can be used in therapeutics for the treatment of cocaine intoxication. The results obtained in the present study show the docking energies of benzoylmethylecgonine with the native and mutated enzymes; -8.6 kcal/mol in BChE, -6.8 kcal/mol in native CocE, -7.2 kcal/mol in mutant CocE. Molecular dynamics studies show that the mean motion (RMSD) of benzoylmethylecgonine at the enzyme binding site is higher in the complex; with BChE; (4.5 Å), followed by native CocE (3.4 Å), being smaller and more stable in mutant CocE (3.0 Å). Finally, the study allows us to conclude that the replacement of the amino acids Leu196 and Ile301 by cysteines shows that the mutant CocE presents less movement during molecular dynamics compared to the native CocE, this would indicate that the mutations probably increase the enzymatic stability at 37 °C