RESUMO
Helicobacter pylori are one of the most common bacterial pathogens in humans whose seropositivity increases with age and low socio-economic status. Due to presence of its pathogenic-island causes chronic persistent and atrophic gastritis in adults and children that often culminate in development of gastric and duodenal ulcers. Studies indicate that infected individuals have two to sixfold increased risk of developing gastric cancer and mucosal associated lymphoid tissue lymphoma compared to their uninfected counterparts. The complete genome sequences have provided a plethora of potential drug targets. Subtractive study holds the promise of providing a conceptual framework for identification of potential drug targets and providing insights to understand the biological regulatory mechanisms in diseases, which are playing an increasingly important role in searching for novel drug targets from the information contained in genomics. In this paper, we discuss subtractive study approaches for identifying drug targets, with the emphasis on the modelling of target protein and docking of the modelled protein with probable ligand by using computational tools.
Assuntos
Antibacterianos/química , Proteínas de Bactérias/química , Desenho de Fármacos , Helicobacter pylori/fisiologia , Simulação de Acoplamento Molecular/métodos , Análise de Sequência de Proteína/métodos , Sequência de Aminoácidos , Proteínas de Bactérias/genética , Sítios de Ligação , Proliferação de Células/genética , Mineração de Dados , Bases de Dados de Proteínas , Marcação de Genes/métodos , Modelos Químicos , Dados de Sequência Molecular , Ligação ProteicaRESUMO
The recent advances in high throughput sequencing technology accelerate possible ways for the study of genome wide variation in several organisms and associated consequences. In the present study, mutations in TGFBR3 showing significant association with FCR trait in chicken during exome sequencing were further analyzed. Out of four SNPs, one nsSNP p.Val451Leu was found in the coding region of TGFBR3. In silico tools such as SnpSift and PANTHER predicted it as deleterious (0.04) and to be tolerated, respectively, while I-Mutant revealed that protein stability decreased. The TGFBR3 I-TASSER model has a C-score of 0.85, which was validated using PROCHECK. Based on MD simulation, mutant protein structure deviated from native with RMSD 0.08 Å due to change in the H-bonding distances of mutant residue. The docking of TGFBR3 with interacting TGFBR2 inferred that mutant required more global energy. Therefore, the present study will provide useful information about functional SNPs that have an impact on FCR traits.
RESUMO
VacA is a high-molecular weight multimeric pore-forming protein encoded by the chromosomal gene vacA of Helicobacter pylori J99 strian. It plays a significant role in the development of gastric cancer in human by inducing the formation of vacuoles. Genomics and proteomics features of an organism have provided a plethora of potential drug targets. The crystal structure of VacA is not available in any structural database; hence a 3D structure is very essential for structural studies and discovery of potential inhibitors against proteins. In this study 3D structure of VacA is modelled a by using Bhageerath: an energy based web enabled computer software suite. According to our study VacA steriochemical validation shows 91.7% residues are in allowed region of Ramachandran plot. Further validation was done by WHAT CHECK to provide evidence that the distribution of the main chain bond lengths and omega bond angles were within limits with Z-score 1.0 and error values are negligible. The modelled protein was submitted to Protein Model Database and can be downloaded with PMDID PM0077963. Further we found that metallo peptidase "M3" cleaves VacA and helps in import mechanism in mitochondria. Structure of metallo peptidase is also not available in any structural database so we modelled and validated its structure. With the help of docking studies we blocked the active site of metallo peptidase by ligand LA3 and 294 with binding energy -5.9 and -5.2 KJ/mol respectively, thus prevented import mechanism of VacA in mitochondria. The inhibitors identified from our study were LA3 and 294 ligands. The investigation concluded that these drugs could be used as the potential inhibitors against the damage of stomach and duodenum, which ultimately reduces the likelihood of ulcer as well as gastric cancer.
Assuntos
Proteínas de Bactérias/química , Infecções por Helicobacter/microbiologia , Helicobacter pylori/química , Metaloproteases/química , Modelos Moleculares , Fatores de Virulência/química , Proteínas de Bactérias/metabolismo , Sítios de Ligação , Simulação por Computador , Bases de Dados de Proteínas , Helicobacter pylori/metabolismo , Helicobacter pylori/patogenicidade , Humanos , Ligantes , Metaloproteases/antagonistas & inibidores , Mitocôndrias/metabolismo , Conformação Molecular , Software , Especificidade da Espécie , Fatores de Virulência/metabolismoRESUMO
Recently WHO and NREVSS collaborating laboratories located in all 50 states, and Washington D.C reported that out of 3,588 specimens,164 were found positive for influenza type (i.e. 4.6%) and from these 164 specimens 162 (i.e. 98.8 %) were of influenza A H1N1 subtype. Comparative study of the past and current reports gives a general idea that the influenza activity deserves high attention from public health authorities in the U.S. In this connection, presently some groups are developing intensive computer-aided research in QSAR, Docking, Molecular Modeling and Drug Design, Sequence Analysis and Phylogenetic analysis of candidate compounds and/or targets; in order to advance in the treatment and/or prevention of this pandemic Flu. In this work, primarily we carry out a mini-review of the more important theoretical studies reported until now within this area, followed by the study of a specific type of target. Keeping in view the nature of this virus, we can conclude that there is always a need to find other target protein as inhibitor other than the existing one. So that this lethal pandemic flu can be treated and prevented further. Therefore, after Neuraminidase and M2 ion channels the surface protein that we can target in H1N1 strain is Hemagglutinins (HA). We use comparative modeling; which is one of the methods that can reliably generate a 3D model for HA protein. Multiple structures of this subtype of Influenza Virus are available at PDB, but we are focused on Influenza A (H1N1). Therefore, methodology of analysis mainly focuses on modeling the structure of this protein and, if possible, finding a probable active sites and inhibitors to it.