Journal d'informatique et de biologie des systèmes

Humans have been carrying unwanted viral gene segments since many years and reports suggests that approximately 3-8% of the human genome has been comprised of viral DNA. In this point of view, various viral sequences were downloaded from NCBI Tax Browser and scanned against complete genome of Homo sapiens for the presence of possible viral inserts in human genome. The results from the computational analysis revealed that dengue virus resulted in viral segments inserted in the intron regions of human genome and exon region insertions were observed with polio and simian enterovirus. The alignments which show > 25-30 residues, 90-100% identities and the sequences located in the exon regions were considered.

Malaria is the most important parasitic disease in humans, with transmission occurring in over 100 countries with a population of three billion people. It is caused by protozoan parasites of the genus Plasmodium. These parasites are transmitted from one person to another by the female anopheles mosquito. Proguanil is a prophylactic antimalarial drug, it stops the malaria parasite, Plasmodium falciparum and Plasmodium vivax, from reproducing once it is in the red blood cells. It does this by inhibiting the enzyme, dihydrofolate reductase. The side effects of these drugs make the need for the necessity of new improved drugs Conformational analysis and geometry optimization of Proguanil was performed using Argus Lab & Hex software. When the receptor (DHFR) was docked with the drug Proguanil the energy value obtained was (-6.59) using Argus Lab and (-174.54) using hex. The most feasible position for the drug to interact with the receptor was found to be with analog 2 having energy -9.56 K.cal/mole using Argus Lab and -201.92 K.cal/mole using HEX Tool. So Proguanil Analog 2 sketched using Chemsketch is detected with more signifi cant energy values in both softwares and probable lead molecules. Further from ADME/T properties of the Analogs is also showing the better result than available drug.

Staphylococcus aureus is one of the most important and studied gram positive bacterial strains, which have a great potential to infect human beings as well as other mammals. The hospital-acquired methicillin-resistant, vancomycinsusceptible gram–positive bacteria strain is responsible for much life threatening diseases like Toxic-shock syndrome, staphylococcal scarlet fever, meningitis, osteomyelitis, etc. This antibiotic resistance strain, lead to development of the new antibiotics or drug molecules which can kill or suppress the growth of Staphylococcus aureus. We have performed an insilico comparative analysis of metabolic pathways of the host Homo sapiens and the pathogen S. aureus. The e-value threshold cut-off was set to 0.005. We have identifi ed total 235 enzyme sequences, which are non homologous to Homo sapiens protein sequences and among them 59 enzymes are found to be essential for survival of the S. aureus according to the DEG database. Further PA-SUB analysis Results showed that about 52.5% enzymes are found to be in the cytoplasm, 13.5% enzymes are found to be in extracellular, 6.7% enzymes are plasma membrane protein and 27.1% enzymes are given no positive prediction. In this comparative analysis, we have also found 5 unique pathways among 59 essential and 23 non homologous enzymes.