In Silico Determination and Validation of OMR Structure and Ligand Binding Site as a vaccine candidate in Acinetobacter baumannii

Donya Jahangir¹ Fateme Sefid²

1) Departeman of biology, Science and Art University Email:
2) Department of Biology, shahed University E-mail:

Publication : International Conference on Science and Engineering(2icesconf.com)
Abstract :
Acinetobacter baumannii is a causative pathogen for severe infections. Treatment of infections caused by this pathogen is a significant problem in human medicine [1]. Iron is an essential element for most pathogens including A. baumannii. Low solubility of the essential element under aerobic conditions or at physiological pH imposes limiting condition to the bacterium [1]. Because of its insufficient free concentration in biological fluids, the bacterium employs strategies to obtain iron in complex forms. Iron-regulated outer membrane proteins (IROMPs) are expressed under iron-restricted conditions in the bacterium [2]. These proteins are also expressed in other bacteria like Pseudomonas aeruginosa, Escherichia coli, and Neisseria gonorrhoeae. These proteins are members of outer membrane proteins (OMPs) and are structurally and functionally different from open porins [3]. Smaller molecules could pass through these porins in the outer membrane (OM). However, molecules above 600 Da must use outer OMP to pass the layer [4-6]. In addition to bactericidal and opsonizing activity, monoclonal antibodies generated against IROMPs can block the iron uptake system in vitro [7]. A greater understanding of the nature of OMR and also its role in serious infections of A. baumannii will help develop new and more effective treatment for Acinetobacter infections. The knowledge of tertiary structure of proteins could help deduction of their functions and also their interactions with other compounds such as ligands [8]. Moreover, rational modification and engineering of proteins depend on understanding their 3D structures [9]. 3D protein structures could be employed in drug and vaccine designs [10] and conformational epitope predictions [11]. The huge number of known protein sequences versus the inconsiderable number of structural annotations highlight necessity of identification of tertiary protein structures [12]. Experimental determination of protein structures remains an important challenge due to its high failure rates. Since experimental determination of 3D protein structures is expensive and time consuming, other approaches are ought to be considered [13]. For outer membrane proteins, purification and crystallization are further obstacles in addition to common experimental determination of 3D protein structures. Nowadays, bioinformatic tools are of interesting advantages for biologists [14, 15]. Prediction of 3D protein structure is one of the wide applications of these tools [16, 17]. Several methods and algorithms are available for protein structure predictions, homology modeling being one of them. Homology modeling is an in silico method for prediction of 3D protein structures based on known homologous protein structures as a template [18]. However 3D structure of OMR is yet not to be determined. The present study undertakes this task.
Keywords : Acinetobacterbaumanni Iron regulated protein Bioinformatics