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Rare earth elements have been shown to trigger the B-to-Z DNA transition in diverse self-assembled branched DNA architectures. Herein, we investigated the influence of cerium chloride on the conformational changes of DNA sequences containing repeated cytosine-guanine (CG) 6-12 or guanine-cytosine (GC) 6-12 sequences. The CD results show that (CG) 6-12 repeats were susceptible to the formation of Z-DNA at low concentrations of CeCl 3 . On the other hand, (GC) 6-12 is unable to undergo B-Z DNA transition and instead exhibits condensation with a similar amount of CeCl 3 . The CD signature was found to be different and unique in both alternate repeats during the interaction with CeCl 3 . The sequence-specific effects on the B-Z transition are based on the order of nucleotides in DNA. With the addition of EDTA, the Z-form of DNA is reverted to the native B-form. Further, we have reported the positive zeta potential of CeCl 3 -induced Z-DNA in contrast to the negative zeta potential of B-DNA. The differential zeta-potential value during the B-Z transition is complementary to the conformational changes of DNA. The molecular simulation study also supports the sequence-specific conformational change between the B- and Z-forms of DNA molecules. This newly described reversible topological and sequence-dependent transition is crucial for understanding the structural and biological roles of Z-DNA in response to CeCl 3 ., Competing Interests: The authors declare no competing financial interest., (© 2024 The Authors. Published by American Chemical Society.)

Cytokines regulate immune responses essential for maintaining immune homeostasis, as deregulated cytokine signaling can lead to detrimental outcomes, including inflammatory disorders. The antioxidants emerge as promising therapeutic agents because they mitigate oxidative stress and modulate inflammatory pathways. Antioxidants can potentially ameliorate inflammation-related disorders by counteracting excessive cytokine-mediated inflammatory responses. A comprehensive understanding of cytokine-mediated inflammatory pathways and the interplay with antioxidants is paramount for developing natural therapeutic agents targeting inflammation-related disorders and helping to improve clinical outcomes and enhance the quality of life for patients. Among these antioxidants, curcumin, vitamin C, vitamin D, propolis, allicin, and cinnamaldehyde have garnered attention for their anti-inflammatory properties and potential therapeutic benefits. This review highlights the interrelationship between cytokines-mediated disorders in various diseases and therapeutic approaches involving antioxidants., Competing Interests: Declaration of Competing Interest The Authors declare no conflict of interests, (Copyright © 2024 The Authors. Published by Elsevier Masson SAS.. All rights reserved.)

The transition from right-handed to left-handed DNA is not only acts as the controlling factor for switching gene expression but also has equal importance in designing nanomechanical devices. The (CG) n and (GC) n repeat sequences are well known model molecules to study B-Z transition in the presence of higher concentration of monovalent cations. In this communication, we report a cyclic transition in (CG) 6 DNA using millimolar concentration of trivalent lanthanide salt LaCl 3 . The controlled and reversible transition was seen in (CG) 12 , and (GC) 12 DNA employing CD spectroscopy. While LaCl 3 failed to induce B-Z transition in shorter oligonucleotides such as (CG) 3 and (GC) 3 , a smooth B-Z transition was recorded for (CG) 6 , (CG) 12 and (GC) 12 sequences. Interestingly, the phenomenon was reversible (Z-B transition) with addition of EDTA. Particularly, two rounds of cyclic transition (B-Z-B-Z-B) have been noticed in (CG) 6 DNA in presence of LaCl 3 and EDTA which strongly suggest that B-Z transition is reversible in short repeat sequences. Thermal melting and annealing behaviour of B-DNA are reversible while the thermal melting of LaCl 3 -induced Z-DNA is irreversible which suggest a stronger binding of LaCl 3 to the phosphate backbone of Z-DNA. This was further supported by isothermal titration calorimetric study. Molecular dynamics (MD) simulation indicates that the mode of binding of La 3+ (of LaCl 3 ) with d(CG) 8 .d(CG) 8 is through the minor groove, wherein, 3 out of 11 La 3+ bridge the anionic oxygens of the complementary strands. Such a tight coordination of La 3+ with the anionic oxygens at the minor groove surface may be the reason for the experimentally observed irreversibility of LaCl 3 -induced Z-DNA seen in longer DNA fragments. Thus, these results indicate LaCl 3 can easily be adopted as an inducer of left-handed DNA in other short oligonucleotides sequences to facilitate the understanding of the molecular mechanism of B-Z transition., (Copyright © 2022 Elsevier B.V. All rights reserved.)

The most remarkable conformational transition in nature is the B-to-Z transition of DNA which not only contributes for epigenetic regulation but also is exploited to create several advanced nanomaterials for sensing and nanomechanics. The present communication focuses on the intrinsic factors that control the La 3+ /Ce 3+ -induced B-to-Z transition in self-assembled branched DNA (bDNA) nanostructures. The transition is sensitive even to two nucleotide change in the loop length and overhang sequences. Predominantly, bDNA structures having 3 T loop length are more sensitive towards helical switching than the 5 T bearing structures. Particularly, bDNA US-17, US-19 and US-23 having 3 T in the loop are showing B-Z transition in presence of LaCl 3 . Interestingly, with 'GATC' overhangs both La 3+ /Ce 3+ -induced B-to-Z transition was noticed in bDNA structures US-21 and US-22 (having 3 T and 5 T in the loop, respectively). The lanthanide-induced B-Z transition in bDNA is reversed with treatment of EDTA. Isothermal titration calorimetry (ITC) experiments show that the binding mode of lanthanide salts to bDNA followed an entropically and enthalpically favorable process. Further, for the first time ITC data suggests the B-to-Z transition in bDNA is a cooperative shift from exothermic to endothermic., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Millimolar concentrations of PrCl 3 can induce sequence-specific B-Z transition in various-self-assembled branched DNA (bDNA) nanostructures. Competitive dye binding and thermal kinetics suggest that the phosphate backbone and grooves of bDNA are wrapped with Pr 3+ for stabilizing the Z-bDNA. Application of EDTA can convert Z-DNA back to the B-form., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)

Since the sulfur specific cleavage is vital for the organic sulfur removal from fossil fuel, we explored potential bacterial strains of MTCC (Microbial Type Culture Collection) to desulfurize the Dibenzothiophene (DBT) through C-S bond cleavage (4-S pathway). MTCC strains Rhodococcus rhodochrous (3552), Arthrobacter sulfureus (3332), Gordonia rubropertincta (289), and Rhodococcus erythropolis (3951) capable of growing in 0.5 mM DBT were examined for their desulfurization ability. The presence of dsz genes as well as the metabolites was screened by polymerase chain reaction (PCR) and HPLC, respectively. All these strains showed > 99% DBT desulfurization with 10 days of incubation in minimal salt medium. From the HPLC analysis it was further revealed that these MTCC strains show differences in the end metabolites and desulfurize DBT differently following a variation in the regular 4-S pathway. These findings are also well corroborating with their respective organization of dszABC operons and their relative abundance. The above MTCC strains are capable of desulfurizing DBT efficiently and hence can be explored for biodesulfurization of petrochemicals and coal with an eco-friendly and energy economical process.

DNA based self-assembled nanostructures and DNA origami has proven useful for organizing nanomaterials with firm precision. However, for advanced applications like nanoelectronics and photonics, large-scale organization of self-assembled branched DNA (bDNA) into periodic lattices is desired. In this communication for the first time we report a facile method of self-assembly of Y-shaped bDNA nanostructures on the cationic surface of Aluminum (Al) foil to prepare periodic two dimensional (2D) bDNA lattice. Particularly those Y-shaped bDNA structures having smaller overhangs and unable to self-assemble in solution, they are easily assembled on the surface of Al foil in the absence of ligase. Field emission scanning electron microscopy (FESEM) analysis shows homogenous distribution of two-dimensional bDNA lattices across the Al foil. When the assembled bDNA structures were recovered from the Al foil and electrophoresed in nPAGE only higher order polymeric bDNA structures were observed without a trace of monomeric structures which confirms the stability and high yield of the bDNA lattices. Therefore, this enzyme-free economic and efficient strategy for developing bDNA lattices can be utilized in assembling various nanomaterials for functional molecular components towards development of DNA based self-assembled nanodevices., (Copyright © 2017 Elsevier Inc. All rights reserved.)

DNA adopts different conformation not only because of novel base pairs but also while interacting with inorganic or organic compounds. Self-assembled branched DNA (bDNA) structures or DNA origami that change conformation in response to environmental cues hold great promises in sensing and actuation at the nanoscale. Recently, the B-Z transition in DNA is being explored to design various nanomechanical devices. In this communication we have demonstrated that Cerium chloride binds to the phosphate backbone of self-assembled bDNA structure and induce B-to-Z transition at physiological concentration. The mechanism of controlled conversion from right-handed to left-handed has been assayed by various dye binding studies using CD and fluorescence spectroscopy. Three different bDNA structures have been identified to display B-Z transition. This approach provides a rapid and reversible means to change bDNA conformation, which can be used for dynamic and progressive control at the nanoscale., (Copyright © 2016 Elsevier Inc. All rights reserved.)