Mycoplasma Phosphoenolpyruvate-Dependent Sugar Phosphotransferase System: Purification and Characterization of Enzyme I

The Mycoplasma phosphoenolpyruvate-dependent sugar phosphotransferase system consists of three components: a membrane-bound enzyme II, a soluble phosphocarrier protein (HPr), and a soluble enzyme I. The soluble enzyme I was purified by ammonium sulfate fractionation; Bio-Gel P-10 gel filtration; acid precipitation; diethylaminoethyl-Bio-Gel A; and Bio-Gel HTP column chromatography. The enzyme I was shown to be homogeneous by electrophoresis in a pH 8.9 non-sodium dodecyl sulfate gel and by isoelectric focusing. Whereas the protein moved as a single component in both the non-sodium dodecyl sulfate gel and isoelectric focusing, on sodium dodecyl sulfate gels, it moved as three subcomponents. The molecular weights of the three subunits, alpha, beta, and gamma, were 44,500, 62,000 and 64,500, respectively. The holoprotein moved as a single component, in the region of 220,000 daltons, in a Bio-Gel A 0.5-agarose column. The molar ratio of subunits was estimated to be 2alpha:1beta:1gamma. The elution characteristics on a diethylaminoethyl column at pH 7.4 and 6.8, acid precipitation data, and amino acid composition indicated that the protein is acidic. Isoelectric focusing occurred at pH 4.8. N-terminal amino acids determined by the dansyl chloride method indicated that glycine, alanine, and tyrosine are N-terminal amino acids of the three subunits. Although the protein was stable for at least 14 months at -20 degrees C, it was irreversibly inactivated by the thiol reagent N-ethyl-maleimide.     

Purification and characterization of methyl-accepting chemotaxis protein methyltransferase I in Bacillus subtilis.

A methyltransferase that methylates one of the proteins involved in chemotactic adaptation to sensory stimuli in Bacillus subtilis was purified to homogeneity. The enzyme utilizes S-adenosylmethionine as donor for a methyl group that is transferred to a glutamate residue in a 69 000-mol.wt. membrane protein and also to a protein of 19 000 mol.wt. The molecular weights of the denatured enzyme by sodium dodecyl sulphate/polyacrylamide-gel electrophoresis and of the native enzyme by gel-filtration chromatography both show the protein to be a 44 000-mol.wt. monomer. Isoelectric focusing of the purified methyltransferase showed the protein to be a single species with isoelectric point pI 5.4. On the basis of a molecular weight of 44 000, the molar absorption coefficient at 262 nm of the enzyme is 10.9 x 10(4) M-1 . cm-1. The Km of the enzyme for S-adenosylmethionine is about 2 microM. The Ki for S-adenosylhomocysteine is about 0.2 microM. Ca2+ is a competitive inhibitor of methylation, with a Ki of 0.065 microM. The enzyme methylates membranes from the wild-type more efficiently than membranes isolated from a mutant strain defective in chemotaxis. The enzyme is unable to methylate Escherichia coli membranes.     

CaСl2 Salt Signaling in Primary Root Architecture and Lateral Root Emergence in Arabidopsis thaliana

Russian Journal of Plant Physiology - Plant root architecture modulates during developmental stages and adjusts with the environmental condition. The cytosolic calcium which is a ubiquitous...     

In vivo glucose-6-phosphatase inhibitory,toxicity and antidiabetic potentials of 2-picolylamine thioureas in Swiss albino mice

The 2-picolylamine is a simplest analogue of the alkaloid that has secondary and tertiary nitrogen function in its cyclic structure like that of alkaloids that can be derivatized to a number of biologically active compounds. In connection to our previous work, in the present work, three thiourea derivatives (I = 1,3-bis(2-benzyl-3-phenyl-1-(pyridine-2-yl) propyl) thiourea, II = 1,3-bis (pyridin-2-ylmethyl) thiourea, and III = 1-(2-benzyl-3-phenyl-1-(pyridine-2-yl) propyl)-3-phenylthiourea) were synthesized using 2-picolylamine template which is a readily available synthetic analogue of naturally occurring alkaloid. The biological effect of the synthesized derivatives were monitored on the activity of glucose-6-phosphatase in Swiss albino mice (21-days). The derivatives were also tested for their potential toxicity in a 28-days sub-chronic toxicity studies by assessing their effects on different parameters like hematological, serum biochemistry and liver histology. The therapeutic effect of the safe derivative (I) was examined in streptozotocin-induced diabetic mice as well. The derivatives showed inhibition of the enzyme activity from good to an excellent degree. Compound I had the highest inhibition with 21.42 ± 5.113 mg of the released phosphate as compared to that of the positive control group (84.55 ± 3.213 mg). Only I turned out to be safe for use in animals without exerting any toxic or lethal effects on any of the assessed parameters in the used animal model. Compound I efficiently reversed the effects like hyperglycemia, hyperlipidemia and weight loss in the test animals. Out of these three-tested compounds, I was found safe to be use as therapeutic agent in diabetes complications. However, further toxicological studies in other animal models are needed as well.     

The Enhancement of Soil Fertility,Dry Matter Transport and Accumulation,Nitrogen Uptake and Yield in Rice via Green Manuring

Readily available chemical fertilizers have resulted in a decline in the use of organic manure (e.g., green manures), a traditionally sustainable source of nutrients. Based on this, we applied urea at the rate of 270 kg ha⁻¹ with and without green manure in order to assess nitrogen (N) productivity in a double rice cropping system in 2017. In particular, treatment combinations were as follows: winter fallow rice-rice (WF-R-R), milk vetch rice-rice (MV-R-R), oil-seed rape rice-rice (R-R-R) and potato crop rice-rice (P-R-R). Results revealed that green manure significantly (p ≤ 0.05) improved the soil chemical properties and net soil organic carbon content increased by an average 117.47%, total nitrogen (N) by 28.41%, available N by 26.64%, total phosphorus (P) by 37.77%, available P by 20.48% and available potassium (K) by 33.10% than WF-R-R, however pH was reduced by 3.30% across the seasons. Similarly, net dry matter accumulation rate enhanced in green manure applied treatments and ranked in order: P-R-R > R-R-R > MV-R-R > WF-R-R. Furthermore, the total leaf dry matter transport (t ha⁻¹ ) for the P-R-R in both seasons was significantly higher by an average 11.2%, 7.2% and 36 % than MV-R-R, R-R-R, and WF-R-R, respectively. In addition, net total nitrogen accumulation (kg ha⁻¹ ) was found higher in green manure applied plots compared to the control. Yield and yield attributed traits were observed maximum in green manure applied plots, with treatments ranking as follows: P-R-R > R-R-R > MV-R-R > WF-R-R. Thus, results obtained highlight ability of green manure to sustainably improve soil quality and rice yield.     

Foliar Concentrations of Selected Elements,Assessment of Oxidative Stress Markers and Role of Antioxidant Defense System is Associated with Fly Ash Stress Tolerance in Withania somnifera

Journal of Plant Growth Regulation - Increased dependence on thermal power has resulted in a significant increase in the generation of fly ash (FA), which exacerbates environmental...     

Viral impacts on honey bee populations: A review

Honey bee is vital for pollination and ecological services, boosting crops productivity in terms of quality and quantity and production of colony products: wax, royal jelly, bee venom, honey, pollen and propolis. Honey bees are most important plant pollinators and almost one third of diet depends on bee’s pollination, worth billions of dollars. Hence the role that honey bees have in environment and their economic importance in food production, their health is of dominant significance. Honey bees can be infected by various pathogens like: viruses, bacteria, fungi, or infested by parasitic mites. At least more than 20 viruses have been identified to infect honey bees worldwide, generally from Dicistroviridae as well as Iflaviridae families, like ABPV (Acute Bee Paralysis Virus), BQCV (Black Queen Cell Virus), KBV (Kashmir Bee Virus), SBV (Sacbrood Virus), CBPV (Chronic bee paralysis virus), SBPV (Slow Bee Paralysis Virus) along with IAPV (Israeli acute paralysis virus), and DWV (Deformed Wing Virus) are prominent and cause infections harmful for honey bee colonies health. This issue about honey bee viruses demonstrates remarkably how diverse this field is, and considerable work has to be done to get a comprehensive interpretation of the bee virology.     

Phytochemical screening and anti-oxidant activity of Sargassum wightii enhances the anti-bacterial activity against Pseudomonas aeruginosa

In this study, the phytochemical, phenolic, flavonoid and bioactive compounds were successfully screened from crude extract of Sargassum wightii by LC-MS analysis after NIST interpretation. Bacterial growth inhibition study result was shown with 24 mm zone inhibition at 200 µg/mL concentration against P. aeruginosa. The increased phenolic content was much closed to gallic acid and the range was observed at 250 μg/mL concentration. In addition, flavonoid contents of the algae extract was indicated more significant with rutin at 200 μg/mL. In result, both the phenolic and flavonoid contents of the extract were more correlated with gallic acid and rutin. Further, the total anti-oxidant and DPPH radical scavenging activities were shown increased activity at 200 μg/mL concentrations. Furthermore, the excellent anti-bacterial alteration result was observed at 200 μg/mL concentration by minimum inhibition concentration. Therefore, the result was revealed that the marine algae Sargassum wightii has excellent phytochemical and anti-oxidant activities, and it has improved anti-bacterial activity against P. aeruginosa.     

The Prooxidant Action of Dietary Antioxidants Leading to Cellular DNA Breakage and Anticancer Effects: Implications for Chemotherapeutic Action Against Cancer

Plant-derived dietary antioxidants have attracted considerable interest in recent past for their ability to induce apoptosis and regression of tumors in animal models. While it is believed that the antioxidant properties of these agents may contribute to lowering the risk of cancer induction by impeding oxidative injury to DNA, it could not account for apoptosis induction and chemotherapeutic observations. In this article, we show that dietary antioxidants can alternatively switch to a prooxidant action in the presence of transition metals such as copper. Such a prooxidant action leads to strand breaks in cellular DNA and growth inhibition in cancer cells. Further, the cellular DNA breakage and anticancer effects were found to be significantly enhanced in the presence of copper ions. Moreover, inhibition of antioxidant-induced DNA strand breaks and oxidative stress by Cu(I)-specific chelators bathocuproine and neocuproine demonstrated the role of endogenous copper in the induction of the prooxidant mechanism. Since it is well established that tissue, cellular, and serum copper levels are considerably elevated in various malignancies, such a prooxidant cytotoxic mechanism better explains the anticancer activity of dietary antioxidants against cancer cells.     

Antifungal and antibacterial activities of Taxus wallichiana Zucc

Current study was undertaken to evaluate the in vitro antifungal and antibacterial potential of methanol extract and subsequent fractions obtained after partitioning in organic solvents with variable polarity of the aerial parts of the tree Taxus wallichiana Zucc. Traditionally, this plant is often used in folk medicines in Pakistan for treating microbial infections. In order to rationalize the traditional use, methanol extracts of leaf, bark, and heartwood of Taxus wallichiana Zucc. were tested against six bacteria and six fungal strains using the Hole diffusion and macro-dilution methods. All extracts and fractions displayed significant antimicrobial effect. Only three fungal strains, Trichophyton longifusus, Microspoum canis, and Fusarium solani were susceptible to the extracts and fractions with MICs ranging from 0.08 to 200 mg/mL. In case of bacterial strains, Staphylococcus aureus, Pseudomonas aeruginosa and Salmonella typhi were susceptible to the extracts and fractions with MICs ranging from 0.08 to 200 mg/mL. Comparison results were carried out using imipinem, miconazole and amphotericin B as standard antibiotics.