MLPA identification of dystrophin mutations and in silico evaluation of the predicted protein in dystrophinopathy cases from India.

BACKGROUND: Duchenne muscular dystrophy (DMD) and Becker muscular dystrophy (BMD) are X-linked recessive disorders caused by mutations in the DMD gene. The aim of this study was to predict the effect of gene mutations on the dystrophin protein and study its impact on clinical phenotype. METHODS: In this study, 415 clinically diagnosed patients were tested for mutations by Multiplex ligation dependent probe amplification (MLPA). Muscle biopsy was performed in 34 patients with negative MLPA. Phenotype-genotype correlation was done using PROVEAN, hydrophobicity and eDystrophin analysis. We have utilized bioinformatics tools in order to evaluate the observed mutations both at the level of primary as well as secondary structure. RESULTS: Mutations were identified in 75.42% cases, of which there were deletions in 91.6% and duplications in 8.30%. As per the reading frame rule, 84.6% out-of frame and 15.3% in-frame mutations were noted. Exon 50 was the most frequently deleted exon and the exon 45-52 region was the hot-spot for deletions in this cohort. There was no correlation noted between age of onset or creatine kinase (CK) values with extent of gene mutation. The PROVEAN analysis showed a deleterious effect in 94.5% cases and a neutral effect in 5.09% cases. Mutations in exon 45-54 (out of frame) and exon 46-54 (in-frame) regions in the central rod domain of dystrophin showed more negative scores compared to other domains in the present study. Hydrophobicity profile analysis showed that the hydrophobic regions I & III were equally affected. Analysis of deletions in hinge III hydrophobic region by the eDystrophin programme also predicted a hybrid repeat seen to be associated with a BMD like disease progression, thus making the hinge III region relatively tolerant to mutations. CONCLUSIONS: We found that, while the predictions made by the software utilized might have overall significance, the results were not convincing on a case by case basis. This reflects the inadequacy of the currently available tools and also underlines the possible inadequacy of MLPA to detect other minor mutations that might enhance or suppress the effect of the primary mutation in this large gene. Next Generation Sequencing or targeted Sanger sequencing on a case by case basis might improve phenotype- genotype correlation.

Modelo molecular teórico del receptor serotoninérgico 5HT2A acoplado a proteína G / Theoretical molecular model of the G protein-coupled 5HT2A serotonergic receptor / Modelo molecular teórico do receptor serotoninérgico 5-HT2A acoplado à proteína G

Objetivo. Construir un modelo molecular teórico de la estructura terciara del receptor 5HT2A de Homo sapiens a partir de estructurasobtenidas experimentalmente como plantillas. Materiales y métodos. Para la realización del modelo teórico se contempló el protocoloestablecido por Ballesteros y Weinstein para la construcción del receptor acoplado proteína G, por medio de alineamiento de la secuenciade aminoácidos, perfiles de hidrofobicidad, refinamiento de bucles por restricciones espaciales, y minimización de energía con el campode fuerza OPLS_2005. Resultados. El modelo obtenido fue validado por el gráfico de Ramachandran con un 91,7% de aminoácidosdentro de los límites establecidos para ángulos phi y psi, y un RMSD de 0,95 Å con respecto a rodopsina de bovino. Conclusiones. Seobtuvo un modelo teórico validado, útil para realización de estudios de acoplamiento ligando-receptor...

Objective Build a theoretical molecularmodel of the tertiary structure of the Homo sapiens 5HT2A receptor from experimentally obtained structures as templates. Materialsand methods In the construction of the theoretical model we considered the protocol established by Ballesteros and Weinstein for theconstruction of the G-protein coupled receptor, by the alignment of the amino acid sequence, hydrophobicity profiles, refinement ofloops by spatial restrictions and energy minimization with the force field OPLS_2005. Results The resulting model was validated bythe Ramachandran plot with 91.7% of amino acids within the limits set for angles phi and psi and a RMSD of 0.95 Å with respect tobovine rhodopsin. Conclusions We obtained a validated theoretical model useful in studies of ligand-receptor docking...

Objetivo. Construir um modelo molecularteórico da estrutura terciária do receptor 5HT2A de Homo Sapiens, com estruturas obtidas experimentalmente como moldes. Materiaise métodos. Para a elaboração do modelo teórico se utilizou o protocolo estabelecido por Ballesteros e Weinstein para a construção doreceptor acoplado à proteína G, por intermédio de alinhamento da seqüência de aminoácidos, perfis de hidrofobicidade, refinamento debucles por restrições espaciais e minimização da energia com o campo de força OPLS_2005. Resultados. O modelo obtido foi validadopelo gráfico de Ramachandran com 91,7% dos aminoácidos dentro dos limites estabelecidos para os ângulos phi e psi, e um RMSD de0,95 Å com respeito à rodopsina de bovino. Conclusões. Obteve-se um modelo teórico validado, útil para a realização de estudos deacoplamento ligante-receptor...