Identification of anti-filarial leads against aspartate semialdehyde dehydrogenase of Wolbachia endosymbiont of Brugia malayi: combined molecular docking and molecular dynamics approaches

Lymphatic filariasis is a debilitating vector borne parasitic disease that infects human lymphatic system by nematode Brugia malayi. Currently available anti-filarial drugs are effective only on the larval stages of parasite. So far, no effective drugs are available for humans to treat filarial infections. In this regard, aspartate semialdehyde dehydrogenase (ASDase) in lysine biosynthetic pathway from Wolbachia endosymbiont Brugia malayi represents an attractive therapeutic target for the development of novel anti-filarial agents. In this present study, molecular modeling combined with molecular dynamics simulations and structure-based virtual screening were performed to identify potent lead molecules against ASDase. Based on Glide score, toxicity profile, binding affinity and mode of interactions with the ASDase, five potent lead molecules were selected. The molecular docking and dynamics results revealed that the amino acid residues Arg103, Asn133, Cys134, Gln161, Ser164, Lys218, Arg239, His246, and Asn321 plays a crucial role in effective binding of Top leads into the active site of ASDase. The stability of the ASDase-lead complexes was confirmed by running the 30 ns molecular dynamics simulations. The pharmacokinetic properties of the identified lead molecules are in the acceptable range. Furthermore, density functional theory and binding free energy calculations were performed to rank the lead molecules. Thus, the identified lead molecules can be used for the development of anti-filarial agents to combat the pathogenecity of Brugia malayi.     

Identification of Hedysarum varieties using amplified fragment length polymorphism on a capillary electrophoresis system.

For non-model organisms that do not have sequence information readily available, amplified fragment length polymorphism (AFLP) is a well-established technique that can be used for genomic mapping applications such as genetic diversity studies or phylogenetic studies. While AFLP can be performed on a variety of systems, including gel-based systems that require multiple labor-intensive steps, the availability of a more automated system that integrates the assay, electrophoresis platform, and analysis software could enable researchers to greatly increase their throughput and facilitate routine AFLP analysis. We demonstrate the use of such a system for AFLP analysis on Hedysarum species. AFLP assays performed on samples belonging to two different species isolated from Utah identified different varieties that clustered as expected from their actual locations.     

Synthesis, DNA-binding ability and evaluation of antitumour activity of triazolo[1,2,4]benzothiadiazine linked pyrrolo[2,1-c][1,4]benzodiazepine conjugates

A series of triazolobenzothiadiazine-pyrrolobenzodiazepine conjugates linked through different alkane spacers have been prepared. These compounds have exhibited significant cytotoxicity against most of the cell lines examined. Compound 5a displays GI(50) values from 1.83 to 2.38 microM against seven human tumour cell lines, and is identified as a promising lead compound from this series. Their DNA thermal denaturation studies have also been carried out, and one of the compounds 5c elevates the DNA helix melting temperature of the CT-DNA by 2.6 degrees C after incubation for 36 h.     

Production of Polyclonal Antibodies Using Recombinant Coat Protein of Papaya ringspot virus and their Use in Immunodiagnosis

Production of polyclonal antibodies requires large amount of purified virus that can be avoided by the use of recombinant coat protein (CP). Recombinant CP of Papaya ringspot virus (PRSV) was thus used for the production of polyclonal antibodies as the virus purification from papaya tissues provides low virus yields. CP was expressed as a fusion protein (～72 kD) containing a fragment of E. coli maltose binding protein. Polyclonal antibodies from rabbits immunized with the fusion protein, successfully detected natural infection of PRSV in papaya and cucurbits samples collected from different locations at 1:4000 dilution in direct antigen-coated enzyme-linked immunosorbent assay.