Antifungal Signature: Physicochemical and Structural In Silico Analysis of Some Antifungal Peptides

High throughput screening of antifungal peptide libraries have generated large number of information on peptide activities. However scientists are still struggling to explain the specific antifungal protein motifs resulting in their activities. So a thorough antifungal peptide optimization is required. To design and predict secondary structure of synthetic as well as natural antifungal peptide using in silico approaches, various parameters such as their sequences, physicochemical characterization, structures and functions should taken care to ensure a successful prediction. The primary interest of this study is to determine the properties that stabilize bonds of helices and coils of antifungal peptides along with their domains. Fifty different antifungal peptides have been analyzed in this study which were retrieved from uniprot and pdb databases and were characterized thoroughly using in silico tools. The present analysis showed that most of the antifungal peptides were hydrophobic in nature due to high content of nonpolar residues where as the functional domains were hydrophilic because of the presence of more polar residues. Many disulphide bonds were noticed in these peptides because of the presence of high cysteine residues which may be regarded as a positive factor for stability of linear helices and coils. Maximum number of random coils were observed in the domains of the studied peptides. The present study thus indicated that the peptidal domains of antifungal peptides contain structurally conserve signature though they are evolutionary diverse. Thus the present in silico models are able to guide the antifungal peptide design in a meaningful way.     

Molecular Cloning, Bacterial Overexpression and Characterization of L-myo- inositol 1- Phosphate Synthase from a Monocotyledonous Resurrection Plant, Xerophyta viscosa Baker

L-myo-inositol 1-phosphate synthase (EC 5.5.1.4; MIPS), an evolutionarily conserved enzyme-protein, catalyses the first and rate limiting step of inositol biosynthesis. Inositol and its derivatives play important roles in biological kingdom like growth regulation, membrane biogenesis, signal transduction and also acts as an osmolyte or osmoprotectant in abiotic stress tolerance. Here we report the cloning, sequencing and the characterization of the INO1 gene from Xerophyta viscosa (XINO1), a monocotyledonous resurrection plant. Nucleotide sequences of XINO1 show striking homology (70–99%) with a number of INO1 genes from plant sources particularly with the monocots. The gene is functionally identified through genetic complementation using a yeast inositol auxotrophic strain FY250. The gene is expressed in E. coli BL21, recombinant protein purified to homogeneity, biochemically characterized and compared with Oryza INO1 (RINO1) gene product. The XINO1 gene product is catalytically active in a broader range of lower temperature (between 10–40 °C) than the RINO1 gene- product. This is the first report of MIPS gene from any resurrection plant.     

Metal accumulation in two contiguous eutrophic peri-urban lakes,Chivero and Manyame,Zimbabwe

Concentrations of aluminium, cadmium, chromium, cobalt, copper, iron, lead, nickel and zinc were determined in surface water, benthic sediments, and the gills, liver and stomach muscle tissues of Oreochromis niloticus and Clarias gariepinus in peri-urban lakes Chivero and Manyame, Zimbabwe. Five sites were sampled in each lake once per month in November 2015, February, May, August and November 2016. Pollution load index detected no metal contamination, whereas the geo-accumulation index reflected heavy to extreme sediment pollution, with Fe, Cd, Zn, Cr, Ni and Cu present in both lakes. Significant spatial temporal variations were detected for Al, Cr, Cu and Pb across sites within and between the two lakes. High Fe, Al and Cr concentrations in water and sediments in lakes Chivero and Manyame derive from geogenic background sources in addition to anthropogenic loads and intensity. Elevated concentrations of Al, Pb, Cu, Cd, Fe and Zn detected in gills, liver and stomach tissue of catfish corroborate concentrations in water and sediments, and pose the highest ecological and health risk for hydrobionts in lakes Chivero and Manyame. Contiguity of peri-urban lakes exposes them to similar threats, necessitating creative water management strategies, which ensure ecological continuity.     

The antidepressant-like effect of Ocimum basilicum in an animal model of depression

We investigated the efficacy of Ocimum basilicum (OB) essential oils for treating depression related behavioral, biochemical and histopathological changes caused by exposure to chronic unpredictable mild stress (CUMS) in mice and to explore the mechanism underlying the pathology. Male albino mice were divided into four groups: controls; CUMS; CUMS plus fluoxetine, the antidepressant administered for pharmacological validation of OB; and CUMS plus OB. Behavioral tests included the forced swim test (FST), elevated plus-maze (EPM) and the open ?eld test (OFT); these tests were performed at the end of the experiment. We assessed serum corticosterone level, protein, gene and immunoexpression of brain-derived neurotropic factor (BDNF) and glucocorticoid receptors (GRs) as well as immunoexpression of glial fibrillary acidic protein (GFAP), Ki67, caspase-3 in the hippocampus. CUMS caused depression in the mice as evidenced by prolonged immobility in the FST, prolonged time spent in the open arms during the EPM test and reduction of open field activity in the OFT. OB ameliorated the CUMS induced depressive status. OB significantly reduced the corticosterone level and up-regulated protein and gene expressions of BDNF and GR. OB reduced CUMS induced hippocampal neuron atrophy and apoptosis, and increased the number of the astrocytes and new nerve cells. OB significantly increased GFAP-positive cells as well as BDNF and GR immunoexpression in the hippocampus.