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The C-terminal Jα-helix of the Avena sativa's Light Oxygen and Voltage (AsLOV2) protein, unfolds on exposure to blue light. This characteristic seeks relevance in applications related to engineering novel biological photoswitches. Using molecular dynamics simulations and the Markov state modeling (MSM) approach we provide the mechanism that explains the stepwise unfolding of the Jα-helix. The unfolding was resolved into seven steps represented by the structurally distinguishable states distributed over the initiation and the post initiation phases. Whereas, the initiation phase occurs due to the collapse of the interaction cascade FMN-Q513-N492-L480-W491-Q479-V520-A524, the onset of the post initiation phase is marked by breaking of the hydrophobic interactions between the Jα-helix and the Iß-strand. This study indicates that the displacement of N492 out of the FMN binding pocket, not necessarily requiring Q513, is essential for the initiation of the Jα-helix unfolding. Rather, the structural reorientation of Q513 activates the protein to cross the hydrophobic barrier and enter the post initiation phase. Similarly, the structural deviations in N482, rather than its integral role in unfolding, could enhance the unfolding rates. Furthermore, the MSM studies on the wild-type and the Q513 mutant, provide the spatiotemporal roadmap that lay out the possible pathways of structural transition between the dark and the light states of the protein. Overall, the study provides insights useful to enhance the performance of AsLOV2-based photoswitches.
Assuntos
Avena , Simulação de Dinâmica Molecular , Proteínas de Plantas , Avena/química , Proteínas de Plantas/químicaRESUMO
Herein, the influence of compositional engineering via active site alternation on catalytic behaviour has been studied for the Ruddlesden-Popper-based system Sm2-xSrxNiO4-δ. A phase change from orthorhombic (x = 0.6) to tetragonal (x = 1.0) in bulk Sm2-xSrxNiO4-δ is confirmed by Rietveld (XRD) analysis, thermogravimetric analysis (TGA) and X-ray photoelectron spectroscopy (XPS). To alter the active sites, we fabricated thin films for x = 0.6 and x = 1.0 using a pulsed laser deposition technique. The electrocatalytic behaviour has been studied in an environmentally friendly medium, i.e., a neutral medium (pH = 7), for both bulk and thin films, and parameters such as transient response, electrochemical reversibility and oxygen evolution reactivity are measured. The cyclic voltammetry curves suggest that electrochemical reversibility for thin films is governed by adsorption as opposed to the diffusion observed for bulk samples. Our investigation further suggests that moderate electroactivity can be achieved with an increase in active sites on miniaturization with the phase change.
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Changes in environmental conditions like temperature and light critically influence crop production. To deal with these changes, plants possess various photoreceptors such as Phototropin (PHOT), Phytochrome (PHY), Cryptochrome (CRY), and UVR8 that work synergistically as sensor and stress sensing receptors to different external cues. PHOTs are capable of regulating several functions like growth and development, chloroplast relocation, thermomorphogenesis, metabolite accumulation, stomatal opening, and phototropism in plants. PHOT plays a pivotal role in overcoming the damage caused by excess light and other environmental stresses (heat, cold, and salinity) and biotic stress. The crosstalk between photoreceptors and phytohormones contributes to plant growth, seed germination, photo-protection, flowering, phototropism, and stomatal opening. Molecular genetic studies using gene targeting and synthetic biology approaches have revealed the potential role of different photoreceptor genes in the manipulation of various beneficial agronomic traits. Overexpression of PHOT2 in Fragaria ananassa leads to the increase in anthocyanin content in its leaves and fruits. Artificial illumination with blue light alone and in combination with red light influence the growth, yield, and secondary metabolite production in many plants, while in algal species, it affects growth, chlorophyll content, lipid production and also increases its bioremediation efficiency. Artificial illumination alters the morphological, developmental, and physiological characteristics of agronomic crops and algal species. This review focuses on PHOT modulated signalosome and artificial illumination-based photo-biotechnological approaches for the development of climate-smart crops.
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Rare earth nickelate perovskites have very wide uses, as magnetic insulators, as well as being conducting materials for the various components of solid oxide fuel cells (SOFCs) due to them undergoing an insulator to metal transition below operating temperature. In SOFCs, the microstructural design of electrode materials is an important aspect for electron and oxygen ion conduction at the electrolyte-electrode and electrode-air interfaces. To investigate this feature, a Ruddlesen-Popper structured layered perovskite, (SmSr)NiO4-δ, was synthesized at different sintering temperatures using a solid-state reaction technique. Porous and dense microstructures were obtained at sintering temperatures of 1250 and 1425 °C, respectively. The influence of electrocatalysis on the structures of both surfaces was studied comprehensively. Post cyclic voltammetry structural studies show the presence of Ni-(OH)2 and Ni-OOH species for the samples, respectively, suggesting that they undergo different oxygen reduction reaction mechanisms.
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CHT7 is a regulator of quiescence repression in Chlamydomonas reinhardtii. Initially, CHT7's repression activity was thought to be managed by its DNA-binding CXC domain. Later, it was found that the CHT7-CXC domain is dispensable for CHT7's activities. Rather, CHT7's predicted protein domains were proposed to be involved in regulation activities by binding to other repressors in the cell. Yet, it remains unclear why and how CHT7 refrains its CXC domain from participating in any transcriptional activities. The question becomes more intriguing, since CXC binding regions are available in promoter regions of some of the misregulated genes in CHT7 mutant (cht7). Through biophysical experiments and molecular dynamics approaches, we studied the DNA recognition behavior of CHT7-CXC. The results indicate that this domain possesses sequence selectivity due to the differential binding abilities of its subdomains. Further, to understand if the case is that CXC loses its DNA binding capabilities in the vicinity of other repressors, we examined CHT7-CXC's DNA binding stability under the spatial constraint conditions created through fusing CHT7-CXC with AsLOV2. The results show limited ability of CHT7-CXC to withstand steric forces and provide insights to why and how algal cells may hold back CHT7-CXC's indulgence in quiescence repression. CLASSIFICATIONS: Biological Sciences, Biophysics and Computational Biology.
Assuntos
Proteínas de Ligação a DNA , Fatores de Transcrição , Triglicerídeos , Hidrólise , Fatores de Transcrição/genética , Proteínas de Ligação a DNA/metabolismo , DNA , Transcrição GênicaRESUMO
Soybean is scientifically known as Glycine max. It belongs to the Fabaceae family. It consists of a lot of bioactive phytochemicals like saponin, phenolic acid, flavonoid, sphingolipids and phytosterols. It also owns excellent immune-active effects in the physiological system. Soy and its phytochemicals have been found to have pharmacological properties that include anticancer, antioxidant, anti-hypercholesterolaemic, anti-diabetic, oestrogenic, anti-hyperlipidaemic, anti-inflammatory, anti-obesity, anti-hypertensive, anti-mutagenic, immunomodulatory, anti-osteoporotic, antiviral, hepatoprotective, antimicrobial, goitrogenic anti-skin ageing, wound healing, neuroprotective and anti-photoageing activities. Present study has been designed to set standard pharmacognostical extraction method, complexation of compounds, qualitative evaluation through phytochemical screening, identification by TLC, physicochemical properties, solubility profile, total phenolic, flavonoid content as well as analytical evaluation or characterisation like UV and FT-IR of methanolic extract of G. max. The final observations like physicochemical properties such as total ash value, LOD and pH were recorded. Phytochemical screenings show the presence of flavonoid, alkaloid, saponin, carbohydrate, tannins, protein, gums and mucilage, fixed oils and fats. The results were found significant. Further in silico studies proved creatinine and euparin to be potent wound healing agents.
Assuntos
Flavonoides , Glycine max , Compostos Fitoquímicos , Extratos Vegetais , Sementes , Espectrometria de Massas em Tandem , Cicatrização , Cicatrização/efeitos dos fármacos , Extratos Vegetais/química , Extratos Vegetais/farmacologia , Espectrometria de Massas em Tandem/métodos , Sementes/química , Glycine max/química , Compostos Fitoquímicos/análise , Compostos Fitoquímicos/química , Compostos Fitoquímicos/farmacologia , Flavonoides/análise , Flavonoides/química , Flavonoides/farmacologia , Metanol/química , Simulação por Computador , Fenóis/análise , Fenóis/química , Fenóis/farmacologia , AnimaisRESUMO
The adsorptive removal of natural montmorillonite (MMT) clay pillared with titanium oxide (Ti-PILC) was examined in this study to see the adsorptive remove of pharmaceutical compounds (PCs): amoxicillin (AMOX), imipramine (IMP), Diclofenac-Sodium (DIF-S), and paracetamol (PCM) from water under a batch-scale study. The post-intercalation changes in clay were investigated with various surface and structural analysis techniques. The results confirm an increase in the surface area, microporosity, and acidic sites (lewis acid) which improved and regulates Ti-PILC interactions with electron-rich PPCPs molecules. The FTIR bands for Si-OH and Al-OH show a shift in MMT, after pillaring, indicates the intercalation of Ti pillared in its interlayer space. The isotherms studies suggested the best fitting of Redlich Peterson models for all pharmaceutical adsorption data. The Langmuir adsorption (maximum) was recorded for Ti-PILC in the order: 82.68 (IMP) > 23.05 (DIF-S) > 20.83 (PCM) > 4.26 (AMOX) mg.g-1 at a fixed adsorbent dose i.e. 0.1 g·L-1. The PCs adsorption kinetics was also evaluated by Pseudo-first-, and second-order model and results showed the best curve fitting for all PCs. Results of regeneration studies showed that modified Ti-PILC could be a low-cost cleaner material for adsorption of pharmaceuticals from water.