Molecular dynamic simulation alpha crystallin adsorption in bulk phase and at water vacuum interface

Abstract

In both civilized and undeveloped countries Tuberculosis is a fundamental killer infective disease and can be considered as a threat among them. Furthermore, due to an increment of drug resistance and substantial level of TB occurrence in human immunodeficiency, virus-infected individuals. Tuberculosis disease is often the result of the bacteria sequestered inside lung macrophages being activated when the immune system of the infected individual is weakened. Bacterium can spend many years in a dormant state inside lung granulomas. Mycobacterium tuberculosis would have two small heat shock proteins: Acr1 and Acr2. Like all SHSPs, these two heat shock proteins share a domain of 90 amino acids called the a-crystallin domain and have divergent N- and C-terminal extensions. The a crystallin protein (sHSP)2 family is ubiquitous throughout nature and carries out a general cellular protective role in preventing aggregation of denatured proteins and facilitating subsequent refolding by other chaperones. As for the Mycobacterium tuberculosis perspective, this function plays an ultimate role which must be able to survive an inhospitable environment while sequestered within phagosomes of alveolar macrophages. This study was actually considered exploration of the possibilities to immobilize the protein interaction with water vacuum interface. A clue of the possibility of immobilization the protein on the surface would be provided by predicting the conformation of the protein adopted on the surface. Molecular dynamics (MD) simulation was carried out to study adsorbed conformation of a crystallin at the water vacuum interface. The preliminary results showed that there were some conformational changes of protein in water phase while the protein was not preferentially adsorbed on the surface at that particular orientation. As the result, there was no significant change of acrystallin protein conformation.