Use of simplified models for theoretical prediction of the interactions between available antibodies and the receptor-binding domain of SARS-CoV-2 spike protein.

The negative impact of infectious diseases like COVID-19 on public health and the global economy is evident. This pandemic represents a significant challenge for the scientific community to develop new practical analytical methods for accurately diagnosing emerging cases. Due to their selectivity and sensitivity, new methodologies based on antigen/antibody interactions to detect COVID-19 biomarkers are necessary. In this context, the theoretical, computational modeling reduces experimental efforts and saves resources for rational biosensor design. This study proposes using molecular dynamics to predict the interactions between the Receptor Binding Domain (RBD) of the SARS-CoV-2 spike protein simplified model and a set of highly characterized antibodies. The binding free energy of the antigen/antibody complexes was calculated for the simplified models and compared against the complete SARS-CoV-2 ectodomain to validate the methodology. The structural data derived from our molecular dynamics and end-point free energy calculations showed a positive correlation between both approximations, with a 0.82 Pearson correlation coefficient; t = 3.661, df = 3, p-value = 0.03522, with a 95% confident interval. Furthermore, we identified the interfacial residues that could generate covalent bonds with a specific chemical surface without perturbing the binding dynamics to develop highly sensitive and specific diagnostic devices. Communicated by Ramaswamy H. Sarma.

Rotavirus VP6 protein as a bio-electrochemical scaffold: Molecular dynamics and experimental electrochemistry.

This paper reports a theoretical and experimental investigation on the recombinant protein rotavirus VP6 as a bioelectrochemical interface. Our motivation arises from the highly active zones of VP6 which can interact with biological structures and metals, as well as its useful features such as self-assembly, polymorphism, and active surface charge. A molecular simulation study was performed to analyze the charge transfer properties of theVP6 trimer under an applied electric field. The electrostatic properties were evaluated via the nonlinear second-order Poisson-Boltzmann equation, using finite element methods based on parameter discretization and calculation of solute/solvent interaction forces, which account for mean-field screening effects. The electrochemical study validated the theoretical predictions for VP6 in their different assemblies (trimers and nanotubes) when they are used as electrodes in 10 mM K3[Fe(CN)6], 1 M KCl. Applying a potential sweep promotes charge transfer, facilitates redox activity of the ferricyanide ion. Furthermore, protein assemblies decreased electrode electrical resistance and enabled gold particle electrodeposition on the protein VP6. These results suggest that VP6 is a promising conductive biomaterial that promotes charge transfer of redox probes and could be used as a new scaffold to create bio-electrochemical interfaces.

Análisis de diferentes variables antropométricas y bioquímicas y su relación con hábitos de vida familiares en población obesa / Analisis of different anthropometric and biochemical variables and its relation to life habits in children with obesity

Objetivo: El objetivo de este estudio ha sido analizar si existe correlación entre el índice da masa corporal (IMC) de los niños con obesidad con los parámetros antropométricos familiares, hábitos de vida y parámetros bioquímicos. Pacientes: niños entre 2-17 años .Todos los pacientes y sus padres rellenaron encuestas donde se recogieron datos personales y habitos de vida. Resultados: Participaron en el estudio 108 niños con obesidad 44,4% niños. Edad media de 10 años (2-17 años). El 56% prepuberales. El IMC medio de 27,8 % (+4,4DS). No encontramos correlación entre el IMC del niño y el nivel de estudios familiar ni con la situación laboral familiar, ni con quién le acompaña por las tardes. Sólo el 4,6% obtienen una puntuación < 3, en calidad de la dieta (KIDMED). Los niños dedican 3,3 horas al día a actividades sedentarias. Se encontró correlación entre el nº total de actividades sedentarias y el IMC del niño (r=0,205;p=0,004). También el peso con IMC de los progenitores(r= 0,427;P<0,001).Solo se correlacionan con el IMC la insulina, péptido C y índice HOMA, por encima de los valores normales. Conclusiones: La actividad sedentaria es uno de los parámetros fundamentales en el desarrollo de la obesidad. Dada la relación del IMC, la insulinemia y el índice HOMA, y teniendo en cuenta que estos valores están por encima de los valores normales, el mantenimiento de esta situación en el tiempo, podría ser el responsable del síndrome metabólico en el adulto (AU)

Objetive: The objective of this study has been to analyze if there is correlation between the body mass index (BMI) of children with obesity with the anthropometric parameters of their relatives and habits of life. Patients: children between 2-17 years of age. All the patients and their parents filled up a survey where they gathered data on anthropometry, and life style. Results: 108 children participated in the study. 44,4% boys. Average age of 10 years (2-17 years). 56% prepubertal. BMI means of 27,8% (+4,4DS). We didn´t found any correlation between the BMI of the child and the familiar level of studies neither with their labor situation. Only 4,6% obtain a score < 3, in quality of the diet (KIDMED). The children dedicate 3.3 hours of the day to sedentary activities. There was correlation between total nº of sedentary activities and the BMI of the boy (r=0,205; p=0,004), and the weight with BMI of the ancestors (r= 0,427; P< 0,001) too. Insulin, peptide C and index HOMA are correlated with BMI, these values are over the normal range. Conclusions: Sedentary activity is one of the fundamental parameters in the development of the obesity. Given the relation between BMI, insulinemia and index HOMA, and considering that these values are upon the normal values, the maintenance of this situation in time, could be the responsible of the metabolic syndrome in the adult (AU)