تازه های بیوتکنولوژی سلولی مولکولی
سال:1395 | دوره:6 | شماره:24 |تعداد مقالات:16

Aim and background: Pathological studies have suggested that formation of fibrous plaques and accumulated masses of amyloid beta peptides in central nervous system is one of the causes to Alzheimer’s disease. Since these diseases depend on conformational structure of protein, we investigate initial conformational changes of Ab (1-42) and Ab (1-40 by molecular dynamic simulations in this paper.Materials and methods: The solution NMR structures of Ab (1-42) and Ab (1-40) (protein data bank: 1IYT 1& BA4) was chosen as a template for comparative modeling. All simulations and data analysis were performed by GROMACS program with the united-atom protein force field. The final sampling simulations were 20-ns MD simulations, 310K and constant pressure (1 bar).Results: The results of RMSD, radius of gyration and solvent accessible surface area showed that structural changes, flexibility and the propensity to aggregation of Ab (1-42) is more than Ab (1-40).Conclusions: The solvent accessible surface area show the hydrophobicity interaction have important role in aggregation and creation of deformed structures. Our data showed that Ab (1-42) have critical role in the development of Alzheimer’s disease.

Aim and Background: Colorectal cancer is the third most common cancer after lung cancer, stomach and liver cancer in the world. Studies have shown that patients with inflammatory disease of the large intestine are at high risk of developing colorectal cancer are located. Several factors make inflammatory bowel disease and colorectal cancer is one of the factors involved, bacteria and toxins derived from them. Research shows that some strains of E. coli can be induced to increase the mutation rate that was established in 2010 by Cuvas-Romas and colleagues. fimC and vat1 Virulence genes in these organisms play an important role in bacteria pathogenicity. This study is to compare the virulence genes in E.coli strains isolated from samples biopsy patients’ inflammatory bowel disease and colorectal cancer, intestinal tissue was performed.Materialsand Methods: 38 biopsies were obtained from intestinal tissue and E.coli bacteria in microbial and biochemical method was identified and isolated. After DNA extraction, strains for virulence genes vat 1, fim C using polymerase chain reaction (PCR), were evaluated.Results: Molecular analysis showed a significant difference between the groups studied the gene vat 1 (p=0.0245) and 42.8% of positive samples were for this gene in normal groups, 87.5% with inflammatory bowel disease87.5 % of patients with colorectal cancer were reported. But there is no significant difference between the groups in terms of fim C gene (P=0.201). And 71.4% of positive samples for this gene in normal groups’ and 93.7% in patients with inflammatory bowel disease73.3 % of patients with colorectal cancer were reported.Conclusion: The results, to confirm the good relationship between virulence genes studied induced inflammation and proliferation by inducing mutation rate.