Saumya K. Patel

Evolutionary and molecular aspects of Indian tomato leaf curl virus coat protein.

Tomato leaf curl disease (ToLCD) is manifested by yellowing of leaf lamina with upward leaf curl, leaf distortion, shrinking of the leaf surface, and stunted plant growth caused by tomato leaf curl virus (ToLCV). In the present study, using computational methods we explored the evolutionary and molecular prospects of viral coat protein derived from an isolate of Vadodara district, Gujarat (ToLCGV-[Vad]), India. We found that the amino acids in coat protein required for systemic infection, viral particle formation, and insect transmission to host cells were conserved amongst Indian strains. Phylogenetic studies on Indian ToLCV coat proteins showed evolutionary compatibility with other viral taxa. Modeling of coat protein revealed a topology similar to characteristic Geminate viral particle consisting of antiparallel β-barrel motif with N-terminus α-helix. The molecular interaction of coat protein with the viral DNA required for encapsidation and nuclear shuttling was investigated through sequence- and structure-based approaches. We further emphasized the role of loops in coat protein structure as molecular recognition interface.

Structural Insights into the Theoretical Model of Plasmodium falciparum NADH Dehydrogenase and its Interaction with Artemisinin and Derivatives: Towards Global Health Therapeutics

It is a continuing quest to uncover the principal molecular targets of malarial parasites to understand the antimalarial activity and mechanism of action of artemisinin, a potent antimalarial. A series of parasite proteins are experimentally validated as potential targets, such as translationally controlled tumor protein (TCTP) and sarco/endoplasmic reticulum membrane calcium ATP-ase (SERCA). The present study addressed the development of a theoretical model of Plasmodium falciparum NADH dehydrogenase with inference from artemisinin in vivo inhibitory activity. We report here the predicted binding modes of artemisinin and its derivatives. The modeled protein resembled the structural architecture of flavoproteins and oxidoreductases, consisting of two Rossmann folds and dedicated binding sites for its cofactors. Docked poses of the ligand dataset revealed its interactions at or near the si face, indicating being activated. This may aid in generation of reactive oxygen species, thereby disrupting the membrane potential of parasite mitochondria and leading to the clearance from the blood. These observations open up new strategies for development of novel therapeutics, or improvement of existing pharmacotherapies against malaria, a major burden for global health.

Epitope-Based Immunoinformatics and Molecular Docking Studies of Nucleocapsid Protein and Ovarian Tumor Domain of Crimean–Congo Hemorrhagic Fever Virus

Crimean–Congo hemorrhagic fever virus (CCHFV), the fatal human pathogen is transmitted to humans by tick bite, or exposure to infected blood or tissues of infected livestock. The CCHFV genome consists of three RNA segments namely, S, M, and L. The unusual large viral L protein has an ovarian tumor (OTU) protease domain located in the N terminus. It is likely that the protein may be autoproteolytically cleaved to generate the active virus L polymerase with additional functions. Identification of the epitope regions of the virus is important for the diagnosis, phylogeny studies, and drug discovery. Early diagnosis and treatment of CCHF infection is critical to the survival of patients and the control of the disease. In this study, we undertook different in silico approaches using molecular docking and immunoinformatics tools to predict epitopes which can be helpful for vaccine designing. Small molecule ligands against OTU domain and protein–protein interaction between a viral and a host protein have been studied using docking tools.

A Computational Approach towards the Understanding of Plasmodium falciparum Multidrug Resistance Protein 1

The emergence of drug resistance in Plasmodium falciparum tremendously affected the chemotherapy worldwide while the intense distribution of chloroquine-resistant strains in most of the endemic areas added more complications in the treatment of malaria. The situation has even worsened by the lack of molecular mechanism to understand the resistance conferred by Plasmodia species. Recent studies have suggested the association of antimalarial resistance with P. falciparum multidrug resistance protein 1 (PfMDR1), an ATP-binding cassette (ABC) transporter and a homologue of human P-glycoprotein 1 (P-gp1). The present study deals about the development of PfMDR1 computational model and the model of substrate transport across PfMDR1 with insights derived from conformations relative to inward- and outward-facing topologies that switch on/off the transportation system. Comparison of ATP docked positions and its structural motif binding properties were found to be similar among other ATPases, and thereby contributes to NBD domains dimerization, a unique structural agreement noticed in Mus musculus Pgp and Escherichia coli MDR transporter homolog (MsbA). The interaction of leading antimalarials and phytochemicals within the active pocket of both wild-type and mutant-type PfMDR1 demonstrated the mode of binding and provided insights of less binding affinity thereby contributing to parasites resistance mechanism.

Molecular interaction of selected phytochemicals under the charged environment of Plasmodium falciparum chloroquine resistance transporter (PfCRT) model

Phytochemicals of Catharanthus roseus Linn. and Tylophora indica have been known for their inhibition of malarial parasite, Plasmodium falciparum in cell culture. Resistance to chloroquine (CQ), a widely used antimalarial drug, is due to the CQ resistance transporter (CRT) system. The present study deals with computational modeling of Plasmodium falciparum chloroquine resistance transporter (PfCRT) protein and development of charged environment to mimic a condition of resistance. The model of PfCRT was developed using Protein homology/analogy engine (PHYRE ver 0.2) and was validated based on the results obtained using PSI-PRED. Subsequently, molecular interactions of selected phytochemicals extracted from C. roseus Linn. and T. indica were studied using multiple-iterated genetic algorithm-based docking protocol in order to investigate the translocation of these legends across the PfCRT protein. Further, molecular dynamics studies exhibiting interaction energy estimates of these compounds within the active site of the protein showed that compounds are more selective toward PfCRT. Clusters of conformations with the free energy of binding were estimated which clearly demonstrated the potential channel and by this means the translocation across the PfCRT is anticipated.

Ocimum basilicum miRNOME revisited: A cross kingdom approach

O. basilicum is medicinally important herb having inevitable role in human health. However, the mechanism of action is largely unknown. Present study aims to understand the mechanism of regulation of key human target genes that could plausibly modulated by O. basilicum miRNAs in cross kingdom manner using computational and system biology approach. O. basilicum miRNA sequences were retrieved and their corresponding human target genes were identified using psRNA target and interaction analysis of hub nodes. Six O. basilicum derived miRNAs were found to modulate 26 human target genes which were associated `with PI3K-AKTand MAPK signaling pathways with PTPN11, EIF2S2, NOS1, IRS1 and USO1 as top 5 Hub nodes. O. basilicum miRNAs not only regulate key human target genes having a significance in various diseases but also paves the path for future studies that might explore potential of miRNA mediated cross-kingdom regulation, prevention and treatment of various human diseases including cancer.

Comparative genome analysis of Plasmodium sp. and identification of unique signature with next generation sequencing technology

Malaria is a malignant disease which is growing all over the world and its causative agent. Plasmodium species easily develops resistant to commonly used antimalarial drugs easily. These empower different strains of Plasmodium e.g. Plasmodium falciparum and Plasmodium vivax to infect humans with malaria.To get the deeper molecular insights, next generation sequencing data were used for further analysis as it has shifted the paradigm of genomics to address biological questions with high confidence and in timely manner. The short reads for above mentioned parasites were retrieved from SRA (Sequence read archive) and de novo assembly was performed. Several novel genes along with known genes were predicted from assembled contigs, Functional annotation followed by gene ontology and pathway analysis. Comparison between species gave structural and functional diversity of the specific genes responsible for disease condition which further can be studied for disease biology.

Meaningful interpretation by reanalyzing the publicly available dataset: A case study of Salvia miltiorrhiza

MicroRNAs are a newly discovered class of non-protein small RNAs with 22-24 nucleotides and evolutionary conserved posttranscriptional regulatory RNAs, which shows an enormous role in several biological and metabolic process. Plant derived miRNA entered into the body fluid and regulated the expression of host mRNA. Salvia miltiorrhiza is an important medicinal plant known for its potent cardiovascular and anticancer activity and hence, it was selected to identify the cross kingdom regulatory mechanism between medicinal plant and human. In this study, total 8 highly stable putative novel miRNA were predicted from the publically available ESTs of Salvia miltiorrhiza, out of which 2 miRNA were found to be regulating 32 target genes in human. Functional annotation, gene ontology and network analysis were carried out based on their significance and find out the association with the prominent disease like cancer and cardiac diseases. The network analysis showed the some important network protein like SOCS2, CD274, STAT3, TRAF3, and CXCL2 with their associated pathways. The predicted miRNA have a significant potential role in cytokine, Apoptosis and EGFR receptor signalling pathways and its biological regulation. It may be further validated using in-vivo experiment for broader picture into their miRNA epigenetic mechanism and action.

200 Structural insights into the theoretical model of Plasmodium falciparum multi drug resistance 1 protein (PfMDR1) and its interaction with phytochemicals as efficacious antimalarial drugs: an in silico and in vitro approach.

theoretical model of Plasmodium falciparum multi drug resistance 1 protein (PfMDR1) and its interaction with phytochemicals as efficacious antimalarial drugs: an in silico and in vitro approach Saumya K. Patel*, Prakash C. Jha, Yogesh Jasrai, Himanshu A. Pandya and Linz George Department of Bioinformatics, Applied Botany Center (ABC); Department of Zoology, Biomedical Technology and Human Genetics, University School of Sciences, Gujarat University, Ahmedabad – 380009, Gujarat, India; School of Chemical Sciences, Central University of Gujarat, Sector-30, Gandhinagar-382030, Gujarat, India *Email: saumya50@gmail.com, Phone: +91-9904522800, +91-7802099714, +91-79-26302578