Characterization of a putative thioredoxin peroxidase prx1 of <Emphasis Type="Italic">Candida albicans</Emphasis>

In this study, we characterized a putative peroxidase Prx1 of Candida albicans by: 1) demonstrating the thioredoxin-linked peroxidase activity with purified proteins, 2) examining the sensitivity to several oxidants and the accumulation of intracellular reactive oxygen species with a null mutant (prx1Δ), a mutant (C69S) with a point mutation at Cys69, and a revertant, and 3) subcelluar localization. Enzymatic assays showed that Prx1 is a thioredoxin-linked peroxidase which reduces both hydrogen peroxide (H₂O₂) and tert-butyl hydroperoxide (t-BOOH). Compared with two other strong H₂O₂ scavenger mutants for TSA1 and CAT1, prx1Δ and C69S were less sensitive to H₂O₂, menadione and diamide at all concentrations tested, but were more sensitive to low concentration of t-BOOH. Intracellular reactive oxygen species accumulated in prx1Δ and C69S cells treated with t-BOOH but not H₂O₂. These results suggest that peroxidase activity of Prx1 is specified to t-BOOH in cells. In both biochemical and physiological cases, the evolutionarily conserved Cys69 was found to be essential for the function. Immunocytochemical staining revealed Prx1 is localized in the cytosol of yeast cells, but is translocated to the nucleus during the hyphal transition, though the significances of this observation are unclear. Our data suggest that PRX1 has a thioredoxin peroxidase activity reducing both t-BOOH and H₂O₂, but its cellular function is specified to t-BOOH.     

Male Out-Migration: A Factor for the Spread of HIV Infection among Married Men and Women in Rural India

Introduction

Thus far, the reasons for increasing HIV prevalence in northern and eastern Indian states are unknown. We investigated the role of male out-migration in the spread of human immunodeficiency virus (HIV) infection through a case-control study in rural India.

Methods

Currently married men and women were recruited from HIV testing and treatment centers across seven selected districts with high rates of male out-migration in eastern and northern India in 2010 using a case-control study design. Case subjects (men: 595, women: 609) were people who tested HIV seropositive and control subjects (men: 611, women: 600) were those tested HIV seronegative. For each gender, we obtained adjusted odds ratios (AORs) and population attributable risks (PARs) for migration, and behavioral factors.

Results

For men, the prevalence of HIV was significantly higher among those with a migration history (AOR, 4·4); for women, the prevalence of HIV was higher among those with migrant husbands (AOR, 2·3). For both genders, the returned male migration (men: AOR, 3·7; women: AOR, 2·8) was significantly associated with higher prevalence of HIV infection. The PAR associated with male migration was higher for men (54·5%–68·6%) than for women (32·7%–56·9%) across the study areas.

Discussion

Male out-migration is the most important risk factor influencing the spread of HIV infection in rural areas with high out-migration rates, thereby emphasizing the need for interventions, particularly, for returned migrants and spouses of those migrants.     

Hypocholesterolemic Effect of Potent Peptide and Bioactive Fraction from Pigeon Pea By-Products in Wistar Rats

International Journal of Peptide Research and Therapeutics - Elevation high plasma cholesterol plays a significant role in promoting the incidence of atherosclerosis and coronary heart disease. In...     

Green synthesis of ZnO nanoparticles for antimicrobial and vegetative growth applications: A novel approach for advancing efficient high quality health care to human wellbeing

The present work aims to synthesize zinc oxide (ZnO) nanoparticles via green approaches using leaf extract of Parthenium hysterophorus. UV–vis and FT-IR tests confirmed the existence of biomolecules, active materials, and metal oxides. The X-ray diffraction structural study exposes the ZnO nanoparticles formation with hexagonal phase structures. SEM and TEM analysis reveal surface morphologies of ZnO nanoparticles and most of them are spherical with a size range of 10 nm. ZnO nanoparticles were revealed strong antimicrobial activity against both bacterial and fungal strains. The germination of seeds and vegetative growth of Sesamum indicum has been greatly improved.     

Antiproliferative and antioxidant properties of nematocysts crude venom from jellyfish Acromitus flagellatus against human cancer cell lines

This study aimed to investigate the antiproliferative and antioxidant properties of crude venom from the nematocyst of Jellyfish Acromitus flagellates on human lung cancer (A549) and liver cancer (HepG2) cell lines. The prepared crude venom was subjected to analyses of the biochemical constituents, protein profiles, antioxidant and anticancer activities by standard methods. The extracted venom was pale-yellow in color and viscous/sticky. The biochemical composition such as, protein (1.547 mg/ml), lipid (0.039 mg/ml) and carbohydrate (0.028 mg/ml) was estimated. Protein profiles were determined by SDS PAGE, the result revealed that the molecular weight range from 205 ? 3.5 kDa. The free radical scavenging activity was analyzed by the reducing potential (56.36%), DPPH (72.47%), hydroxyl (68.50%), superoxide anion (65.75%), and nitric oxide (33.04%). The cell viability was observed by using different concentrations (20 to 100 µg/ml) of crude venom on A549 and HepG2 cancer cell lines and the IC₅₀ values were recorded in (60 μg/ml and 40 μg/ml) respectively, while it had none cytotoxic effects on Vero cell line up to the concentration of 90 μg/ml. These results suggest that crude venom from nematocyst of A. flagellatus possesses anti-cancer activity and able to develop novel drugs on marine-derived compounds.     

Binding Interactions of Naringenin and Naringin with Calf Thymus DNA and the Role of β-Cyclodextrin in the Binding

The interaction of naringenin (Nar) and its neohesperidoside, naringin (Narn), with calf thymus deoxyribonucleic acid (ctDNA) in the absence and the presence of β-cyclodextrin (β-CD) was investigated. The interaction of Nar and Narn with β-CD/ctDNA was analyzed by using absorption, fluorescence, and molecular modeling techniques. Docking studies showed the existence of hydrogen bonding, electrostatic and phobic interaction of Nar and Narn with β-CD/DNA. 1:2 stoichiometric inclusion complexes were observed for Nar and Narn with β-CD. With the addition of ctDNA, Nar and Narn resulted into the fluorescence quenching phenomenon in the aqueous solution and β-CD solution. The binding constant K _b and the number of binding sites were found to be different for Nar and Narn bindings with DNA in aqueous and β-CD solution. The difference is attributed to the structural difference between Nar and Narn with neohesperidoside moiety present in Narn.