The Role of Calcium-activated Potassium Channel in Mitochondria-Associated ER Membrane and Its Functional Link to Cell Survival and Death

The process of apoptosis is not only regulated by molecular gens but it is also regulated by cellular ionic homeostasis especially K+ homeostasis in the cell. In the past decade, molecular mechanisms of ionic regulation of apoptosis have been extensively investigated. The ionic mechanism of apoptosis are involves Ca2+ influx and accumulation of intracellular Ca2+ is convincing evidence to excessive K+ efflux resulting in early steps in apoptosis. The BK channels play a critical role in mediating the K+ efflux linked with apoptotic cell shrinkage. Mitochondria-associated ER membranes (MAMs) control Ca2+ influx between ER and mitochondria. The BKα subunits are localized in the inner mitochondrial and ER membrane and directly interact with other BK channel associated proteins (BKAPs) like, IP3R-1, calreticulin at the ER face of the MAMs, and the molecular chaperone grp78, which bridges the IP3R-1 with voltage-dependent anion channel (VDAC-1) of the outer mitochondrial membrane (OMM). The present chapter clearly depicts that how BK channels are associated with BKAPs and how they are involved in apoptosis through regulation of K+ efflux

DFT Simulation of Berberine Chloride with Spectroscopic Characterization – Biological activity and Molecular Docking against Breast Cancer

In this work, the structural and spectroscopic properties of the berberine chloride molecule were investigated using quantum chemical calculations based on density functional theory (DFT). Through molecular docking simulation, the breast cancer inhibitory properties of the title chemical were revealed. With the basis set at 6-311++G (d,p), the optimization was carried out and theoretically assigned vibrational frequencies were compared to the experimentally observed vibrational frequencies. The reactive behavior of berberine chloride was further examined using simulated calculations of the molecular electrostatic potential surface. Utilizing the HOMO-LUMO energies, the stability and molecular reactivity of the molecule were assessed and the calculated energy gap was 3.19 eV. The second order perturbation energy E(2) values of the molecule, which demonstrate the bioactivity of the berberine chloride, were determined using natural bond orbital analysis. The Mulliken atomic charge distribution confirms the molecule’s reactive site. The biological activities of berberine chloride were evaluated through in vitro and in silico methods. The antioxidant activity was tested through ABTS assay and the antibacterial test was performed through disk diffusion technique and the zone of inhibition was observed for berberine chloride molecule. The breast cancer inhibitory potential of berberine chloride was assessed through molecular docking simulation. Berberine chloride was docked against seven breast cancer associated proteins and the highest binding ability was observed against HER-2 protein with −9.1 Kcal/mol. The drug-likeness properties were predicted and safety profile of berberine chloride was revealed.</p

Theoretical Investigation of 5-Fluorouracil and Tamoxifen Complex – Structural, Spectrum, DFT, ADMET and Docking Simulation

Combination of FDA approved drugs may be more effective in biological activities by targeting different protein mechanism at a same time and less toxic. A combination of 5-Fluorouracil and tamoxifen may cause a synergistic effect and induce cancer cell death and more effective against corona virus. In this study, constructed 5-Fluorouracil with tamoxifen structure was optimized through DFT/B3LYP approach with the basis set 6-311 G. Theoretical, ultraviolet-visible spectrum was calculated, and electronic transitions were examined. The energy gap between HOMO and LUMO was used to study the combined structure’s structural stability and reactivity and the computed energy gap (ΔE) was 4.3023825 eV. The Mulliken charge distribution was assessed and the atomic charges were calculated. The molecular docking simulation was performed with breast cancer and SARS-CoV-19 target proteins. The docking scores showed that the complex compound’s binding affinity was higher, that confirms better synergistic effect of 5-Fluorouracil and tamoxifen. The complex compound’s maximum binding affinity was −8.0 Kcal/mol against caspase 6 and −8.1 Kcal/mol against furin, that showed inhibitory potential against cancer and corona virus. The pharmacokinetic properties and toxicity of the complex structure was studied, and the results showed the safety profile of the complex lead compound and can be utilized as an effective anticancer and antiviral drug.</p

Ubiquitous lens α-, β-, and γ-crystallins accumulate in anuran cornea as corneal crystallins

Corneal epithelium is known to have high levels of some metabolic enzymes such as aldehyde dehydrogenase in mammals, gelsolin in zebrafish, and α-enolase in several species. Analogous to lens crystallins, these enzymes and proteins are referred to as corneal crystallins, although their precise function is not established in any species. Although it is known that after lentectomy, the outer cornea undergoes transdifferentiation to regenerate a lens only in anuran amphibians, major proteins expressed in an anuran cornea have not been identified. This study therefore aimed to identify the major corneal proteins in the Indian toad (Bufo melanostictus) and the Indian frog (Rana tigrina). Soluble proteins of toad and frog corneas were resolved on two-dimensional gels and identified by matrix-assisted laser desorption ionization time-of-flight/time-of-flight and electrospray ionization quadrupole time-of-flight. We report that anuran cornea is made up of the full complement of ubiquitous lens α-, β-, and γ-crystallins, mainly localized in the corneal epithelium. In addition, some taxon-specific lens crystallins and novel proteins, such as α- or β-enolase/γ-crystallin, were also identified. Our data present a unique case of the anuran cornea where the same crystallins are used in the lens and in the cornea, thus supporting the earlier idea that crystallins are essential for the visual functions of the cornea as they perform for the lens. High levels of lens α-, β-, and γ-crystallins have not been reported in the cornea of any species studied so far and may offer a possible explanation for their inability to regenerate a lens after lentectomy. Our data that anuran cornea has an abundant quantity of almost all the lens crystallins are consistent with its ability to form a lens, and this connection is worthy of further studies

Guanidine&ndash;Curcumin Complex-Loaded Amine-Functionalised Hollow Mesoporous Silica Nanoparticles for Breast Cancer Therapy

The current study focuses on developing a tumour-targeted functionalised nanocarrier that wraps hollow mesoporous silica nanoparticles. The guanidine carbonate and curcumin are immobilised on the surface of 3-aminopropyl-triethoxy silane (APTES)-decorated hollow mesoporous silica nanoparticles (HMSNP), as confirmed through XPS and NMR analysis. XPS analysis demonstrates that the shape of the hysteresis loops is modified and that pore volume and pore diameter are consequently decreased compared to control. Guanidine (85%) and guanidine&ndash;curcumin complex (90%) were successfully encapsulated in HMSNAP and showed a 90% effective and sustained release at pH 7.4 for up to 72 h. Acridine orange/ethidium bromide dual staining determined that GuC-HMNSAP induced more late apoptosis and necrosis at 48 and 72 h compared with Gu-HMNSAP-treated cells. Molecular investigation of guanidine-mediated apoptosis was analysed using western blotting. It was found that cleaved caspases, c-PARP, and GSK-3&beta; (Ser9) had increased activity in MCF-7 cells. GuC-HMSNAP increased the activity of phosphorylation of oncogenic proteins such as Akt (Ser473), c-Raf (Ser249), PDK1 (Ser241), PTEN (Ser380), and GSK-3&beta; (Ser9), thus inducing cell death in MCF-7 cells. Altogether, our findings confirm that GuC-HMNSAP induces cell death by precisely associating with tumour-suppressing proteins, which may lead to new therapeutic approaches for breast cancer therapy