A influência da eletrostática na estabilidade de proteínas cold shock homólogas

Abstract

In the last decades, proteins have been a target of remarkable industrial interest. The functions that such molecules perform have demonstrated benefits in the most variety of areas, such as the pharmacological, food, and biofuel production industries. In this scenario, understanding the aspects that influence protein stability could be relevant for the rational feasibilization and optimization of these molecules. However, the stability of a protein is dependent of a wide set of different interactions, which makes such comprehension a challenge. With this perspective, this work aimed to investigate the role of electrostatic interactions on the stability of the native state of four homologous Cold shock proteins. These proteins have differing stabilities, and such interactions are one of the pointed causes. For this study, we employed a series of simplified theoretical models. We used the Tanford-Kirkwood solvent accessibility model to investigate the influence of each ionizable amino acid residue on the stability of every protein. We also adopted the local frustration model to recognize highly frustrated sites in the structure of each protein. Through this model, we also analyzed the influence of electrostatics over the amount of these sites in every protein. Lastly, we used the alpha-carbon structure-based model and its modified version, that takes into account electrostatics, to study the folding process of each protein. The results obtained from such models confirmed the importance of electrostatics in the stability differentiation of each protein, showing agreement with experimental studies.