Purification and characterization of a thermoalkaline, cellulase free thermostable xylanase from a newly isolated Anoxybacillus sp. Ip-C from hot spring of Ladakh

An alkaline, highly thermostable cellulase free xylanase was purified from a thermophilic Anoxybacillus sp. Ip-C, newly isolated from hot spring of Ladakh. The enzyme was purified using ammonia sulphate precipitation followed by Sephadex G-75. The molecular weight of the xylanase was about 45 kDa, as analyzed by SDS-PAGE. The enzyme had optimum activity at pH 9.0 and 70ºC temperature; the enzyme retained 90% of its original activity for 96 hrs at 70 ºC. Vmax and Km of the enzyme were found to be 13.5 µmol min-1 mg-1 protein and 4.59 mg ml-1, respectively. Metal ions, Ca+2, Fe+2 and Mg+2 highly enhance the enzyme activity to 122.45, 119.06 and 118.98% respectively; whereas SDS and Hg+2 completely inhibit (0 U/ml) the enzyme activity. TLC analysis of enzymatic hydrolysis products showed that this xylanase is an endoxylanase, and generates xylooligosaccharides. Thus, it provides a potential thermostable alkaline xylanase for industrial applications

Effect of heterogeneous substrate adhesivity of follower cells on speed and tension profile of leader cells in primary keratocyte collective cell migration

In single keratocyte motility, membrane tension is reported to be high at cell-fronts and believed to establish front coherence. To understand role of membrane mechanics in collective cell migration, we study membrane height fluctuations in cell sheets from fish scales using interference reflection microscopy (IRM). We report the monolayer to have cells lacking substrate adhesion and show that such ‘non-sticky’ cells can form bridges between leader cells and far-away follower cells. Do such interactions alter motility and membrane mechanics in such leaders? We find non-significant, but reduced speed for leaders with ‘non-sticky’ followers in comparison to other leaders. Cells show high phenotypic variability in their membrane fluctuation tension profiles. On average, this tension is found to be lower at cell fronts than the mid-section. However, leaders with non-sticky followers are more prone to display higher tension at their front and have a negative correlation between cell speed and front-mid tension difference. Thus, we conclude that intracellular tension gradients are heterogeneous in cell sheets and substrate adhesivity of followers can control the coupling of the gradient to cell speed

Altered expression of DNA Methyltransferases in biomass using rural women in West Bengal

Unprocessed solid biomass such as wood, coal, dung and agricultural residues are still used in many rural households in India as main source of domestic energy for cooking, boiling water and heating. Combustion of biomass releases a considerable amount of particulate matters (PM) and toxic pollutants. Therefore, use of biomass as fuels causes very high level of indoor air pollution (IAP) in rural households and the women who do most of the daily household cooking with these fuels, receive the maximum exposure. Thus, the cells of the nasopharynx, oral cavity, airways and the lungs in these women get severely affected and undergo harmful changes. The present study is conducted to appraise the effects of IAP generated PMs and/or carcinogens on epigenetic changes in airway epithelial cells as little information is known about it. In the present study LPG using rural women were used as controls against biomass using rural women and both these groups comprise of non-smokers and non-chewer of tobacco and betel nut. Significantly enhanced production of ROS was evident in biomass fuel users with depletion of SOD, a major scavenger enzyme in comparison to LPG using control women. Furthermore, Immunocytochemical evaluation showed significantly increased expressions of DNMT1 and DNMT3a enzymes and reduced expression of SET7, an inhibitor of DNMT1, in airway epithelial cells of biomass-using rural women in comparison to LPG using control women. The findings indicate major epigenetic changes in airway epithelial cells of biomass users due to long-term exposure to particulate pollution which also increases the risk of lung cancer in these women

Revolutionizing the Biological Landscape: the Power of Genome Editing

In recent decades, the advent of genome editing has brought about profound transformations in biology, allowing for precise modifications to the genetic material of living organisms beyond traditional genetic manipulation methods. This summary explores the vast potential, diverse applications, and ethical considerations associated with genome editing. Led by CRISPR-Cas9, this technology revolutionizes genetic engineering by providing unparalleled accuracy and versatility. Scientists can now manipulate genes with unprecedented precision, impacting various fields such as agriculture and medicine. Genome editing facilitates the creation of genetically modified organisms with desirable traits, from enhancing crop disease resistance to pioneering human therapies. Moreover, it sheds light on gene function, offering crucial biological insights. Despite its transformative potential, ethical concerns accompany genome editing, especially in terms of editing the germ line and its implications for future generations. This necessitates ongoing discussions to address unintended consequences, highlighting the importance of responsible use. Ultimately, genome editing represents a revolutionary advancement with the potential to transform agriculture, medicine, and our understanding of life. Moving forward, inclusive dialogues involving scientists, ethicists, policymakers, and the public are essential to ensure the responsible application of genome editing for the benefit of humanity and the environment

Direct Catalytic Enantioselective Vinylogous Aldol Reaction of Allyl Ketones to Pyrazole-4,5-diones

The first catalytic enantioselective vinylogous nucleophilic addition to pyrazole-4,5-diones is reported. Using quinine-derived bifunctional tertiary amino-amide as the catalyst, this direct aldol reaction of allyl ketones is shown to proceed exclusively in gamma- and E-selective manner to generate pyrazolone derivatives, bearing an oxygen-containing quaternary stereogenic center, in good yields with moderate to high enantioselectivities (up to 97:3 er)

Catalytic enantioselective Michael addition of deconjugated butyrolactams to maleimides

The first catalytic enantioselective Michael addition of deconjugated butyrolactams to N-arylmaleimides is developed with the help of a bifunctional tertiary aminosquaramide catalyst. Unlike the widely explored and structurally related vinylogous nucleophile - deconjugated butenolides, deconjugated butyrolactams are found to be exclusively alpha-selective. The resulting highly substituted and densely functionalized products, bearing contiguous all-carbon quaternary and tertiary stereocenters, are formed in good yields with moderate diastereoselectivity and good to excellent enantioselectivity (up to 99:1 er)

Direct Catalytic Enantioselective Vinylogous Aldol Reaction of Allyl Ketones to Pyrazole-4,5-diones

The first catalytic enantioselective vinylogous nucleophilic addition to pyrazole-4,5-diones is reported. Using quinine-derived bifunctional tertiary amino-amide as the catalyst, this direct aldol reaction of allyl ketones is shown to proceed exclusively in γ- and <i>E</i>-selective manner to generate pyrazolone derivatives, bearing an oxygen-containing quaternary stereogenic center, in good yields with moderate to high enantioselectivities (up to 97:3 er)