Mitochondrial associated ubiquitin fold modifier-1 mediated protein conjugation in Leishmania donovani

In this report, we demonstrate the existence of the ubiquitin fold modifier-1 (Ufm1) and its conjugation pathway in trypanosomatid parasite Leishmania donovani. LdUfm1 is activated by E1-like enzyme LdUba5. LdUfc1 (E2) specifically interacted with LdUfm1 and LdUba5 to conjugate LdUfm1 to proteinaceous targets. Mass spectrometry analysis revealed that LdUfm1 is conjugated to Leishmania protein targets that are associated with mitochondria. Immunofluorescence experiments showed that Leishmania Ufm1, Uba5 and Ufc1 are associated with the mitochondria. The demonstration that all the components of this system as well as the substrates are associated with mitochondrion suggests it may have physiological roles not yet described in any other organism. Overexpression of a non-conjugatable form of LdUfm1 and an active site mutant of LdUba5 resulted in reduced survival of Leishmania in the macrophage. Since mitochondrial activities are developmentally regulated in the life cycle of trypanosomatids, Ufm1 mediated modifications of mitochondrial proteins may be important in such regulation. Thus, Ufm1 conjugation pathway in Leishmania could be explored as a potential drug target in the control of Leishmaniasis.     

Evaluation of diversity of Bacilli from chickpea rhizosphere by 16S ARDRA and assessment of their plant-growth-promoting attributes

A total of eight motile, aerobic, Gram-positive and straight rod-shaped, endospore forming Bacillus spp. were isolated from rhizosphere of chickpea plants collected from different agricultural fields. Phylogeny of isolates was studied by partial sequencing of 16S rDNA and comparative analysis of the sequence data confirmed that the isolates belong to distinct phylogenetic lineage corresponding to Bacillus. Phenotyping clusters correlate with ARDRA pattern and showed resemblance to partial 16S rDNA sequencing. Bacillus spp. BSK5 and Bacillus subtilis BSK17 were the most potent strains for having plant-growth-promoting attributes. These two strains solubilised inorganic phosphate, produced Indole acetic acid, siderophore, Hydrocyanic acid and secreted extracellular chitinase and mild β-1,3-glucanase which antagonised and caused mycelial deformities in two phytopathogens Macrophomina phaseolina and Fusarium oxysporum in dual culture and by culture filtrate.     

Peptidoglycan Hydrolases of Probiotic Pediococcus acidilactici NCDC 252: Isolation,Physicochemical and In Silico Characterization

International Journal of Peptide Research and Therapeutics - Pediococcus acidilactici NCDC 252 is a Gram-positive lactic acid bacteria (LAB) that is being studied to develop it as probiotic and...     

Immunogenicity of Seven-Valent Pneumococcal Conjugate Vaccine Administered at 6, 14 and 40 Weeks of Age in South African Infants

Background

The high cost of pneumococcal conjugate vaccine (PCV) and local epidemiological factors contributed to evaluating different PCV dosing-schedules. This study evaluated the immunogenicity of seven-valent PCV (PCV7) administered at 6-weeks; 14-weeks and 9-months of age.

Methods

250 healthy, HIV-unexposed infants were immunized with PCV7 concurrently with other childhood vaccines. Serotype-specific anti-capsular IgG concentrations were measured one-month following the 1^st and 2^nd PCV-doses, prior to and two-weeks following the 3^rd dose. Opsonophagocytic killing assay (OPA) was measured for three serotypes following the 2^nd and 3^rd PCV7-doses. Immunogenicity of the current schedule was compared to a historical cohort of infants who received PCV7 at 6, 10 and 14 weeks of age.

Results

The proportion of infants with serotype-specific antibody ≥0.35 µg/ml following the 2^nd PCV7-dose ranged from 84% for 6B to ≥89% for other serotypes. Robust antibody responses were observed following the 3^rd dose. The proportion of children with OPA ≥8 for serotypes 9V, 19F and 23F increased significantly following the 3^rd PCV7-dose to 93.6%; 86.0% and 89.7% respectively. The quantitative antibody concentrations following the 2^nd PCV7-dose were comparable to that after the 3^rd -dose in the 6-10-14 week schedule. Geometric mean concentrations (GMCs) following the 3^rd PCV7-dose were higher for all serotypes in this study compared to the historical cohort.

Conclusions

The studied PCV7 dosing schedule induced good immune responses, including higher GMCs following the 3^rd-dose at 9-months compared to when given at 14-weeks of age. This may confer longer persistence of antibodies and duration of protection against pneumococcal disease.     

Alteration in mitochondrial thiol enhances calcium ion dependent membrane permeability transition and dysfunction in vitro: a cross-talk between mtThiol, Ca2+, and ROS

Mitochondrial permeability transition (MPT) and dysfunctions play a pivotal role in many patho-physiological and toxicological conditions. The interplay of mitochondrial thiol (mtThiol), MPT, Ca(2+) homeostasis, and resulting dysfunctions still remains controversial despite studies by several research groups. Present study was undertaken to ascertain the correlation between Ca(2+) homeostasis, mtThiol alteration and reactive oxygen species (ROS) in causing MPT leading to mitochondrial dysfunction. mtThiol depletion significantly enhanced Ca(2+) dependent MPT (swelling) and depolarization of mitochondria resulting in release of pro-apoptotic proteins like Cyt c, AIF, and EndoG. mtThiol alteration and Ca(2+) overload caused reduced mitochondrial electron flow, oxidation of pyridine nucleotides (NAD(P)H) and significantly enhanced ROS generation (DHE and DCFH-DA fluorescence). Studies with MPT inhibitor (Cyclosporin A), Ca(2+) uniport blocker (ruthenium red) and Ca(2+) chelator (BAPTA) indicated that mitochondrial dysfunction was more pronounced under dual stress of altered mtThiol and Ca(2+) overload in comparison with single stress of excessive Ca(2+). Transmission electron microscopy confirmed the changes in mitochondrial integrity under stress. Our findings suggest that the Ca(2+) overload itself is not solely responsible for structural and functional impairment of mitochondria. A multi-factorial cross-talk between mtThiol, Ca(2+) and ROS is responsible for mitochondrial dysfunction. Furthermore, minor depletion of mtThiol was found to be an important factor along with Ca(2+) overload in triggering MPT in isolated mitochondria, tilting the balance towards disturbed functionality.     

Synthesis and antidyslipidemic activity of chalcone fibrates

A series of chalcone based PPAR-α agonists were synthesized and evaluated for their antidyslipidemic activity in high fructose high fat fed dyslipidemic Syrian golden hamsters. Most of the compounds exhibited antidyslipidemic activity. The compounds 4c and 4f have been identified as most potent antidyslipidemics. A definite structure-activity relationship was observed while varying the nature as well as the position of the substituent.     

A study to evaluate the effect of nootropic drug-piracetam on DNA damage in leukocytes and macrophages

Piracetam is a nootropic drug that protects neurons in neuropathological and age-related diseases and the activation and modulation of peripheral blood cells in patients with neuropathological conditions is well known. Therefore, in the present study, in vivo, ex vivo, and in vitro tests were conducted to investigate the effect of piracetam on leukocytes and macrophages. Lipopolysaccharide (LPS) causes oxidative DNA damage; thus, in the present study, LPS was used as a tool to induce DNA damage. In vivo experiments were conducted on Sprague Dawley rats, and piracetam (600mg/kg, oral) was provided for five consecutive days. On the fifth day, a single injection of LPS (10mg/kg, i.p.) was administered. Three hours after LPS injection, blood leukocytes and peritoneal macrophages were collected and processed, and a variety of different assays were conducted. Ex vivo treatments were performed on isolated rat blood leukocytes, and in vitro experiments were conducted on rat macrophage cell line J774A.1. Cell viability and the level of reactive oxygen species (ROS), mitochondrial membrane potential (MMP) and DNA damage were estimated in untreated (control) and piracetam-, LPS- and LPS+piracetam-treated leukocytes and macrophages. In vivo experiments revealed that rats pretreated with piracetam were significantly protected against LPS-induced increases in ROS levels and DNA damage. Ex vivo isolated leukocytes and J774A.1 cells treated with LPS exhibited augmented ROS levels and DNA damage, which were attenuated with piracetam treatment. Thus, the present study revealed the salutary effect of piracetam against LPS-induced oxidative stress and DNA damage in leukocytes and macrophages.     

Vibrational dynamics and heat capacity in polyglycine II

The earlier works on the vibrational dynamics of polyglycine II (PG II) suffer from several infirmities, which not only suppress the dynamical nature of normal modes, but also lead to several incorrect assignments and interactive constants of the potential field. In this study, we have re-examined the phonon dispersion profiles of PG II using Higgs method for evaluation of phase-related normal modes and have attempted to remove the infirmities, as far as possible. The Wilson's GF matrix method combined with the Urey-Bradley force field has been used for normal mode analysis. This potential field leads to correct assignments of Raman, infrared and inelastic neutron scattering frequencies. Characteristic features of the dispersion curve (v versus delta/pi plot), such as repulsion and regions of high density-of-states have been interpreted. In addition, the heat capacity as a function of temperature has been obtained via density-of-states. It agrees well with the experimental data and is being reported for the first time.