Polimorfismos del gen Butirilcolinesterasa responsables de reacciones adversas en pacientes consumidores de “cocaína”

La butirilcolinesterasa humana (BChE; EC 3.1.1.8) es una enzima polimórfica sintetizada en el hígado y en el tejido adiposo, ampliamente distribuida en el organismo y encargada de hidrolizar algunos ésteres de colina como la procaína, ésteres alifáticos como el ácido acetilsalicílico, fármacos como la metilprednisolona, el mivacurium y la succinilcolina y drogas de uso y/o abuso como la heroína y la cocaína. Es codificada por el gen BCHE (OMIM 177400), habiéndose identificado más de 100 variantes, algunas no estudiadas plenamente, además de la forma más frecuente, llamada usual o silvestre. Diferentes polimorfismos del gen BCHE se han relacionado con la síntesis de enzimas con niveles variados de actividad catalítica. Las bases moleculares de algunas de esas variantes genéticas han sido reportadas, entre las que se encuentra las variantes Atípica (A), fluoruro-resistente del tipo 1 y 2 (F-1 y F-2), silente (S), Kalow (K), James (J) y Hammersmith (H). En este estudio, en un grupo de pacientes se aplicó el instrumento validado Lifetime Severity Index for Cocaine Use Disorder (LSI-C) para evaluar la gravedad del consumo de “cocaína” a lo largo de la vida. Además, se determinaron Polimorfismos de Nucleótido Simple (SNPs) en el gen BCHE conocidos como responsables de reacciones adversas en pacientes consumidores de “cocaína” mediante secuenciación del gen y se predijo el efecto delos SNPs sobre la función y la estructura de la proteína, mediante el uso de herramientas bio-informáticas. El instrumento LSI-C ofreció resultados en cuatro dimensiones: consumo a lo largo de la vida, consumo reciente, dependencia psicológica e intento de abandono del consumo. Los estudios de análisis molecular permitieron observar dos SNPs codificantes (cSNPs) no sinónimos en el 27.3% de la muestra, c.293A>G (p.Asp98Gly) y c.1699G>A (p.Ala567Thr), localizados en los exones 2 y 4, que corresponden, desde el punto de vista funcional, a la variante Atípica (A) [dbSNP: rs1799807] y a la variante Kalow (K) [dbSNP: rs1803274] de la enzima BChE, respectivamente. Los estudios de predicción In silico establecieron para el SNP p.Asp98Gly un carácter patogénico, mientras que para el SNP p.Ala567Thr, mostraron un comportamiento neutro. El análisis de los resultados permite proponer la existencia de una relación entre polimorfismos o variantes genéticas responsables de una baja actividad catalítica y/o baja concentración plasmática de la enzima BChE y algunas de las reacciones adversas ocurridas en pacientes consumidores de cocaína.Human Butyrylcholinesterase (BChE; EC 3.1.1.8) is a polymorphic enzyme synthesized in the liver and adipose tissue, widely distributed in the body and responsible for hydrolyze some choline esters such as procaine, aliphatic esters such as aspirin, drugs as methylprednisolone, mivacurium and succinylcholine and drug to use and abuse such as heroin and cocaine. It is coded by the BCHE gene (OMIM 147400), more than 100 variants have been identified, however not all of them have been studied fully, besides the most common form: usual or wild type. BCHE polymorphisms have been shown to produce enzymes with varying levels of catalytic activity. The molecular bases of some genetic variants of BCHE have been reported, such as the Atypical (A), fluoride-resistant 1 and 2 (F-1 and F2), silent (S), Kalow (K), James (J) and Hammersmith (H) variants. In this study, validated instrument Lifetime Severity Index for Cocaine Use Disorder (LSI-C) was applied to evaluate the severity of the consumption of "cocaine" throughout life. In addition, Single Nucleotide Polymorphisms (SNPs) were identified in the BCHE gene, responsible for adverse reactions in patients consumers of "cocaine" by gene sequencing and the effect of these SNPs on the function and structure of the protein was predicted, using bio-informatics tools. The LSI-C instrument provided results in four dimensions: consumption throughout life, recent use, psychological dependence and quit attempt of cocaine use. Molecular analysis studies allowed to observe two coding SNPs (cSNPs) in 27.3% of the sample, c.293A>G (p.Asp98Gly) and c.1699G>A (p.Ala567Thr), located in exons 2 and 4, which are, from the functional point of view, to the atypical variant (A) [dbSNP: rs1799807] and Kalow variant (K) [dbSNP: rs1803274] of BChE enzyme, respectively. In silico prediction established for SNPs p.Asp98Gly a pathogenic character, while for the SNPs p.Ala567Thr showed neutral behavior. The analysis of the results allows proposing the existence of a relationship between polymorphisms or genetic variants responsible for the low catalytic activity and/or low plasma concentration of BChE enzyme and some of the adverse reactions in cocaine consumer patients

Polimorfismos del gen Butirilcolinesterasa responsables de reacciones adversas en pacientes consumidores de “cocaína”

La butirilcolinesterasa humana (BChE; EC 3.1.1.8) es una enzima polimórfica sintetizada en el hígado y en el tejido adiposo, ampliamente distribuida en el organismo y encargada de hidrolizar algunos ésteres de colina como la procaína, ésteres alifáticos como el ácido acetilsalicílico, fármacos como la metilprednisolona, el mivacurium y la succinilcolina y drogas de uso y/o abuso como la heroína y la cocaína. Es codificada por el gen BCHE (OMIM 177400), habiéndose identificado más de 100 variantes, algunas no estudiadas plenamente, además de la forma más frecuente, llamada usual o silvestre. Diferentes polimorfismos del gen BCHE se han relacionado con la síntesis de enzimas con niveles variados de actividad catalítica. Las bases moleculares de algunas de esas variantes genéticas han sido reportadas, entre las que se encuentra las variantes Atípica (A), fluoruro-resistente del tipo 1 y 2 (F-1 y F-2), silente (S), Kalow (K), James (J) y Hammersmith (H). En este estudio, en un grupo de pacientes se aplicó el instrumento validado Lifetime Severity Index for Cocaine Use Disorder (LSI-C) para evaluar la gravedad del consumo de “cocaína” a lo largo de la vida. Además, se determinaron Polimorfismos de Nucleótido Simple (SNPs) en el gen BCHE conocidos como responsables de reacciones adversas en pacientes consumidores de “cocaína” mediante secuenciación del gen y se predijo el efecto delos SNPs sobre la función y la estructura de la proteína, mediante el uso de herramientas bio-informáticas. El instrumento LSI-C ofreció resultados en cuatro dimensiones: consumo a lo largo de la vida, consumo reciente, dependencia psicológica e intento de abandono del consumo. Los estudios de análisis molecular permitieron observar dos SNPs codificantes (cSNPs) no sinónimos en el 27.3% de la muestra, c.293A>G (p.Asp98Gly) y c.1699G>A (p.Ala567Thr), localizados en los exones 2 y 4, que corresponden, desde el punto de vista funcional, a la variante Atípica (A) [dbSNP: rs1799807] y a la variante Kalow (K) [dbSNP: rs1803274] de la enzima BChE, respectivamente. Los estudios de predicción In silico establecieron para el SNP p.Asp98Gly un carácter patogénico, mientras que para el SNP p.Ala567Thr, mostraron un comportamiento neutro. El análisis de los resultados permite proponer la existencia de una relación entre polimorfismos o variantes genéticas responsables de una baja actividad catalítica y/o baja concentración plasmática de la enzima BChE y algunas de las reacciones adversas ocurridas en pacientes consumidores de cocaína.Human Butyrylcholinesterase (BChE; EC 3.1.1.8) is a polymorphic enzyme synthesized in the liver and adipose tissue, widely distributed in the body and responsible for hydrolyze some choline esters such as procaine, aliphatic esters such as aspirin, drugs as methylprednisolone, mivacurium and succinylcholine and drug to use and abuse such as heroin and cocaine. It is coded by the BCHE gene (OMIM 147400), more than 100 variants have been identified, however not all of them have been studied fully, besides the most common form: usual or wild type. BCHE polymorphisms have been shown to produce enzymes with varying levels of catalytic activity. The molecular bases of some genetic variants of BCHE have been reported, such as the Atypical (A), fluoride-resistant 1 and 2 (F-1 and F2), silent (S), Kalow (K), James (J) and Hammersmith (H) variants. In this study, validated instrument Lifetime Severity Index for Cocaine Use Disorder (LSI-C) was applied to evaluate the severity of the consumption of "cocaine" throughout life. In addition, Single Nucleotide Polymorphisms (SNPs) were identified in the BCHE gene, responsible for adverse reactions in patients consumers of "cocaine" by gene sequencing and the effect of these SNPs on the function and structure of the protein was predicted, using bio-informatics tools. The LSI-C instrument provided results in four dimensions: consumption throughout life, recent use, psychological dependence and quit attempt of cocaine use. Molecular analysis studies allowed to observe two coding SNPs (cSNPs) in 27.3% of the sample, c.293A>G (p.Asp98Gly) and c.1699G>A (p.Ala567Thr), located in exons 2 and 4, which are, from the functional point of view, to the atypical variant (A) [dbSNP: rs1799807] and Kalow variant (K) [dbSNP: rs1803274] of BChE enzyme, respectively. In silico prediction established for SNPs p.Asp98Gly a pathogenic character, while for the SNPs p.Ala567Thr showed neutral behavior. The analysis of the results allows proposing the existence of a relationship between polymorphisms or genetic variants responsible for the low catalytic activity and/or low plasma concentration of BChE enzyme and some of the adverse reactions in cocaine consumer patients

Structural Protein Effects Underpinning Cognitive Developmental Delay of the PURA p.Phe233del Mutation Modelled by Artificial Intelligence and the Hybrid Quantum Mechanics–Molecular Mechanics Framework

A whole-exome capture and next-generation sequencing was applied to an 11 y/o patient with a clinical history of congenital hypotonia, generalized motor and cognitive neurodevelopmental delay, and severe cognitive deficit, and without any identifiable Syndromic pattern, and to her parents, we disclosed a de novo heterozygous pathogenic mutation, c.697_699del p.Phe233del (rs786204835)(ACMG classification PS2, PM1, PM2, PP5), harbored in the PURA gene (MIM*600473) (5q31.3), associated with Autosomal Dominant Mental Retardation 31 (MIM # 616158). We used the significant improvement in the accuracy of protein structure prediction recently implemented in AlphaFold that incorporates novel neural network architectures and training procedures based on the evolutionary, physical, and geometric constraints of protein structures. The wild-type (WT) sequence and the mutated sequence, missing the Phe233, were reconstructed. The predicted local Distance Difference Test (lDDT) for the PURAwt and the PURA–Phe233del showed that the occurrence of the Phe233del affects between 220–320 amino acids. The distortion in the PURA structural conformation in the ~5 Å surrounding area after the p.Phe233del produces a conspicuous disruption of the repeat III, where the DNA and RNA helix unwinding capability occurs. PURA Protein–DNA docking corroborated these results in an in silico analysis that showed a loss of the contact of the PURA–Phe233del III repeat domain model with the DNA. Together, (i) the energetic and stereochemical, (ii) the hydropathic indexes and polarity surfaces, and (iii) the hybrid Quantum Mechanics–Molecular Mechanics (QM–MM) analyses of the PURA molecular models demarcate, at the atomic resolution, the specific surrounding region affected by these mutations and pave the way for future cell-based functional analysis. To the best of our knowledge, this is the first report of a de novo mutation underpinning a PURA syndrome in a Latin American patient and highlights the importance of predicting the molecular effects in protein structure using artificial intelligence algorithms and molecular and atomic resolution stereochemical analyses