Biophysical characterization of G protein ectodomain of group B human respiratory syncytial virus from E. coli

Human respiratory syncytial virus (hRSV) is an important pathogen of acute respiratory tract infection. The G protein of hRSV is a transmembrane glycoprotein that is a neutralizing antigen and is thus a vaccine candidate. In this study, synthetic codon optimized ectodomain G protein [G(ΔTM)] of BA genotype of group B hRSV was cloned, expressed, and characterized using biophysical techniques. The molar absorption coefficient and mean residue ellipticity at 222 nm ([θ]222) of G (ΔTM) was found to be 7950 M^?1 cm^?1 and ?19701.7 deg cm² dmol^-1 respectively. It was concluded that G(ΔTM) mainly consist of α-helix (74.9%) with some amount of β-sheet (4%). The protein was stable up to 85°C without any transition curve. However, heat-induced denaturation of G(ΔTM) resulted in total loss of β-sheet whereas not much change was observed in the α-helix part of the secondary structure. It was concluded that G(ΔTM) is an α-helical protein and it is highly stable at high temperature, but could be easily denatured using high concentrations of GdmCl/urea or acidic condition. This is the first investigation of cloning, expression, and characterization of G(ΔTM) of BA viruses from India. Structural characterization of G protein will assist in drug designing and vaccine development for hRSV.     

Sodium and boron exclusion in two Brassica juncea cultivars exposed to the combined treatments of salinity and boron at moderate alkalinity

Salinity and high boron (B) concentrations are important co-limitations to crop production on naturally occurring alkaline soils in low rainfall regions of the world. Although the interactive effects of salinity and B toxicity on Brassica juncea growth have been reported in slightly acidic soils, very little is known about the interactive effects in alkaline soils. In the current study, a moderately tolerant (Vaibhav) and sensitive (Xinyou5) variety, were grown hydroponically for four weeks to assess mild salinity (50 mM NaCl) with or without high B (1 mM B) at moderate alkalinity (pH 8.5/5 mM NaHCO₃). The growth of the two varieties was more affected under the combined treatment than either salinity or high B alone. Although growth rate reduction was similar among the varieties, Vaibhav maintained a lower sodium (Na) and B and a higher potassium (K) concentration in the leaves than Xinyou5. In response to salinity, Vaibhav demonstrated essential tolerance mechanisms of partial exclusion and presumably compartmentalization of Na, leading to greater biomass than Xinyou5. Despite being able to better exclude B, Xinyou5 suffered a greater growth penalty, indicating higher B sensitivity than Vaibhav. In conclusion, screening for individual stresses is not necessarily the best strategy because plant responses to a single stress either salinity or high B may not always be the same as observed when both stresses are present together. Therefore, Brassica germplasm screening is essential for stresses in combination but not separately.     

Carbonic anhydrase inhibitors. Inhibition of human tumor-associated isozymes IX and cytosolic isozymes I and II with some 1,3,4-oxadiazole-thiols

A series of chiral 1,3,4-oxadiazole-5-thiols incorporating 2-substituted-benzenesulfonamide moieties has been prepared from amino acids, via the ester and carbohydrazide intermediate, followed by cyclization with carbon disulfide. Some of these compounds have been investigated for the inhibition of three physiologically relevant carbonic anhydrase (CA, EC 4.2.1.1) isoforms, the human cytosolic hCA I and II, and the human, transmembrane, tumor-associated isozyme hCA IX. All these compounds showed weak (millimolar) affinity for the three isozymes, except two carbohydrazides and two heterocyclic thiols which selectively inhibited the tumor-associated isozyme with inhibition constants around 10 microM. Such compounds constitute interesting lead molecules for the possible design of CA IX-selective inhibitors.     

Stability of proteins in the presence of polyols estimated from their guanidinium chloride-induced transition curves at different pH values and 25 degrees C

We have recently concluded from the heat-induced denaturation studies that polyols do not affect deltaG(D) degrees (the Gibbs free energy change (deltaG(D)) at 25 degrees C) of ribonuclease-A and lysozyme at physiological pH and temperature, and their stabilizing effect increases with decrease in pH. Since the estimation of deltaG(D) degrees of proteins from heat-induced denaturation curves requires a large extrapolation, the reliability of this procedure for the estimation of deltaG(D) degrees is always questionable, and so are conclusions drawn from such studies. This led us to measure deltaG(D) degrees of ribonuclease-A and lysozyme using a more accurate method, i.e., from their isothermal (25 degrees C) guanidinium chloride (GdmCl)-induced denaturations. We show that our earlier conclusions drawn from heat-induced denaturation studies are correct. Since the extent of unfolding of heat- and GdmCl-induced denatured states of these proteins is not identical, the extent of stabilization of the proteins by polyols against heat and GdmCl denaturations may also differ. We report that in spite of the differences in the structural nature of the heat- and GdmCl-denatured states of each protein, the extent of stabilization by a polyol is same. We also report that the functional dependence of deltaG(D) of proteins in the presence of polyols on denaturant concentration is linear through the full denaturant concentration range. Furthermore, polyols do not affect the secondary and tertiary structures of the native and GdmCl-denatured states.     

Conformational and thermodynamic characterization of the premolten globule state occurring during unfolding of the molten globule state of cytochrome c

It has already been shown that the mutant Leu94Gly of horse cytochrome c exists in a molten globule (MG) state. We have carried out studies of reversible folding and unfolding induced by LiCl of this mutant at pH 6.0 and 25 °C by observing changes in the difference molar absorption coefficient at 402 nm, the mean residue ellipticity at 222 nm, and the difference mean residue ellipticity at 409 nm. This process is a three-state process when measured by these probes. The stable folding intermediate state has been characterized by far- and near-UV circular dichroism, tryptophan fluorescence, 8-anilino-1-naphthalenesulfonic acid binding, and dynamic light scattering measurements, which led us to conclude that the intermediate is a premolten globule (PMG). Analysis of the reversible unfolding transition curves for the stability of different states in terms of the Gibbs free energy change at pH 6.0 and 25 °C led us to conclude that the MG state is more stable than the PMG state by 5.4 ± 0.1 kcal mol⁻¹, whereas the PMG state is more stable than the denatured (D) state by only 1.1 ± 0.1 kcal mol⁻¹. A comparison of the conformational and thermodynamic properties of the LiCl-induced PMG state at pH 6.0 with those of the PMG state induced by NaCl at pH 2.0 suggests that a similar PMG state is obtained under both denaturing conditions. Differential scanning calorimetry measurements suggest that heat induces a reversible two-state transition between MG and D states.     

Platanic Acid-Aryl Enones as Potential Anticancer Compounds: Synthesis and Biological Profiling against Breast,Prostate and Lung Cancer Cell Lines

A series of rationally designed platanic acid-based compounds derived from naturally occurring betulinic acid were synthesized through a sequence of Lemieux-Johnson oxidation and Aldol condensation reaction. All the compounds were screened for cytotoxicity against a panel of human cancer and normal cell lines using MTT assay. From the biological data, it was observed that some of these semi-synthetic congeners exhibited potent biological profiles compared to platanic acid. One of the compounds with the p-tolyl substitution was found to be most active in this study, and its cytotoxicity against two of the cell lines, MDA-MB 231 and A-549 were in tune with the standard compound, 5-fluorouracil.     

Differentiation and regenerative capacities of human odontoma-derived mesenchymal cells

Regenerating human tooth ex vivo and biological repair of dental caries are hampered by non-viable odontogenic stem cells that can regenerate different tooth components. Odontoma is a developmental dental anomaly that may contain putative post-natal stem cells with the ability to differentiate and regenerate in vivo new dental structures that may include enamel, dentin, cementum and pulp tissues. We evaluated odontoma tissues from 14 patients and further isolated and characterized human odontoma-derived mesenchymal cells (HODCs) with neural stem cell and hard tissue regenerative properties from a group of complex odontoma tissues from 1 of 14 patients. Complex odontoma was more common (9 of 14) than compound type and females (9 of 14) were more affected than males in our set of patients. HODCs were highly proliferative like dental pulp stem cells (DPSCs) but demonstrated stronger neural immunophenotype than both DPSCs and mandible bone marrow stromal cells (BMSCs) by expressing higher levels of nestin, Sox 2 and βIII-tubulin. When transplanted with hydroxyapatite/tricalcium phosphate into immunocompromised mice, HODCs differentiated and regenerated calcified hard tissues in vivo that were morphologically and quantitatively comparable to those generated by DPSCs and BMSCs. When transplanted with polycaprolactone (biodegradable carrier), HODCs differentiated to form new predentin on the surface of a dentin platform. Newly formed predentin contained numerous distinct dentinal tubules and an apparent dentin–pulp arrangement. HODCs represent unique odontogenic progenitors that readily commit to formation of dental hard tissues.     

Embryonic Microglia Interact with Hypothalamic Radial Glia during Development and Upregulate the TAM Receptors MERTK and AXL following an Insult

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Role of Zinc Oxide Nanoparticles in Countering Negative Effects Generated by Cadmium in Lycopersicon esculentum

Journal of Plant Growth Regulation - Nanotechnology now plays a revolutionary role in many applications; nanomaterials have experienced significant importance in both basic and applied sciences as...