Optimization of Potassium Supply under Osmotic Stress Mitigates Oxidative Damage in Barley

Potassium (K) is the most abundant cation in plants, playing an important role in osmoregulation. Little is known about the effect of genotypic variation in the tolerance to osmotic stress under different K treatments in barley. In this study, we measured the interactive effects of osmotic stress and K supply on growth and stress responses of two barley cultivars (Hordeum vulgare L.) and monitored reactive oxygen species (ROS) along with enzymatic antioxidant activity and their respective gene expression level. The selected cultivars (cv. Milford and cv. Sahin-91Sahin-91) were exposed to osmotic stress (−0.7 MPa) induced by polyethylene glycol 6000 (PEG) under low (0.04 mM) and adequate (0.8 mM) K levels in the nutrient solution. Leaf samples were collected and analyzed for levels of K, ROS, kinetic activity of antioxidants enzymes and expression levels of respective genes during the stress period. The results showed that optimal K supply under osmotic stress significantly decreases ROS production and adjusts antioxidant activity, leading to the reduction of oxidative stress in the studied plants. The cultivar Milford had a lower ROS level and a better tolerance to stress compared to the cultivar Sahin-91. We conclude that optimized K supply is of great importance in mitigating ROS-related damage induced by osmotic stress, specifically in drought-sensitive barley cultivars.

In-Silico Molecular Docking and Pharmaco-Kinetic Activity Analysis of Potential Inhibitors against SARS-CoV-2 Spike Glycoproteins

Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-COV-2) is a causative agent of the potentially fatal coronavirus disease (COVID-19). Coronavirus targets the human respiratory system primarily. It can also infect the gastrointestinal, hepatic, and central nervous systems of humans, avians, bats, livestock, mice, and many other wild animals, as these are primary targets of the pathogen. This study aims to screen out the most potent inhibitor for SARS-CoV-2 (COVID-19) spike glycoproteins among the selected drugs, and computational tools have been utilized for this purpose. The selected drugs have been designed to explore their structural properties in this study by molecular orbital calculation. To inhibit the spike glycoproteins, the performance of these drugs was also examined by molecular docking calculation. In improving the performance of drugs, non-bond interactions play a significant role. To determine the chemical reactivity of all the medicines, HOMO and LUMO energy values were also calculated. The combined calculations exhibited that Ledipasvir among the selected drugs can be the most potent drug to treat SARS-CoV-2 compared to other medications.

The Effect of Pseudoephedrine (Sudafed) on Kinetic activity and histology of Livers and Kidneys in Albino Mice

Pseudoephedrine (PSE) or (Sudafed) is one of the sympathomimetic group of drugs (ephedrine, PSE and amphetamines) which effects cardiovascular system, respiratory system, and gastrointestinal tract. However, only little researches had supported its effect on solid abdominal organs. This study aims to investigate the effects of different doses of Sudafed in the liver and kidney of albino mice. The current study included 18 albino mice grouped into 2 groups: control (3 mice), and acute group (15 mice). The acute group was further subdivided into 5 subgroups, each subgroup of 3mice wasgiven a lonely intaperitonial injection of 0.3ml of the following conc. (500mg/kg, 250mg/kg, 125mg/kg, 62.52mg/kg, and 31.24mg/kg) for 24hrs. After the mentioned period, the mice of all subgroups were sacrificed and the livers and kidneys were removed, processed, sectioned and stained for histological analysis. Results of liver analysis using 500mg/Kg Sudafed intraperitoneallyshowed mild ballooning degeneration of hepatocytes and central vein congestion, while lower doses (250mg/Kg – 31.42mg/Kg) revealed less prominent effect or no significant pathological changes.Moreover, sections from the kidney with the 500mg/Kg Sudafed intraperitoneally showed mild hydropic swelling of tubular epithelium with congestion of intertubular blood vessels and relatively healthy glomeruli. Lower doses revealed no significant pathological changes. Conclusion: The present study demonstrated various pathological effects of PSE on kinetic activity, and histology of Livers and Kidneys of albino mice.

The Vibrio cholerae SpeG Spermidine/Spermine N-Acetyltransferase Allosteric Loop and β6-β7 Structural Elements Are Critical for Kinetic Activity

Polyamines regulate many important biological processes including gene expression, intracellular signaling, and biofilm formation. Their intracellular concentrations are tightly regulated by polyamine transport systems and biosynthetic and catabolic pathways. Spermidine/spermine N-acetyltransferases (SSATs) are catabolic enzymes that acetylate polyamines and are critical for maintaining intracellular polyamine homeostasis. These enzymes belong to the Gcn5-related N-acetyltransferase (GNAT) superfamily and adopt a highly conserved fold found across all kingdoms of life. SpeG is an SSAT protein found in a variety of bacteria, including the human pathogen Vibrio cholerae. This protein adopts a dodecameric structure and contains an allosteric site, making it unique compared to other SSATs. Currently, we have a limited understanding of the critical structural components of this protein that are required for its allosteric behavior. Therefore, we explored the importance of two key regions of the SpeG protein on its kinetic activity. To achieve this, we created various constructs of the V. cholerae SpeG protein, including point mutations, a deletion, and chimeras with residues from the structurally distinct and non-allosteric human SSAT protein. We measured enzyme kinetic activity toward spermine for ten constructs and crystallized six of them. Ultimately, we identified specific portions of the allosteric loop and the β6-β7 structural elements that were critical for enzyme kinetic activity. These results provide a framework for further study of the structure/function relationship of SpeG enzymes from other organisms and clues toward the structural evolution of members of the GNAT family across domains of life.

Production of Long-Acting CNGRC–CPG2 Fusion Proteins: New Derivatives to Overcome Drug Immunogenicity of Ligand-Directed Enzyme Prodrug Therapy for Targeted Cancer Treatment

Objectives: Aminopeptidase N (APN) is an enzyme highly expressed in metastatic cancers and could be used in targeted cancer therapy. Our previous work showed the successful construction of CNGRC–carboxypeptidase G2 (CPG2) and CNGRC–CPG2–CNGRC fusion proteins. Our conjugates and prodrugs were effective in targeting high APN-expressing cancer cells. In the present study, we aim to produce long-acting fusion proteins to overcome 2 of the main drawbacks of antibody-directed enzyme prodrug therapy. Methods: N-terminal and N-, C-terminal fusion CPG2, CNGRC–CPG2, and CNGRC–CPG2–CNGRC, respectively, were PEGylated using polyethylene glycol (PEG) maleimide (40K). We examined the effect of PEGylation on the therapeutic efficacy of the new products. The resulting PEGylated fusion proteins were tested for their stability, ex vivo immunotoxicity, binding capacity to their target on high HT1080, and low A549 APN-expressing cells. The catalytic activity of the resulting PEGylated fusion CPG2 proteins was investigated. Pro-drug “ZD2767P” cytotoxic effect in association with PEG CPG2–CNGRC fusion proteins on cancer cells was studied. Results: Our work demonstrated that the properties of the PEGylated single-fused proteins were significantly improved over that of un-PEGylated fused CPG2, and its kinetic activity and APN-binding affinity were not negatively affected by the PEGylation. Significantly, The PEGylated single-fused CPG2 had lower immunogenicity than the un-PEGylated CPG2. Our results, however, were different in the case of the PEGylated double-fused CPG2. Although its stability in human serum under physiological conditions was not significantly affected, the kinetic activity and its binding affinity to their cellular marker (APN) were substantially reduced. When the study was performed with high and low APN-expressing cancer cell lines, using the prodrug ZD2767p, the PEGylated fusion CPG2 demonstrated cancer cell killing effects. Conclusion: We have successfully produced PEGylated-CNGRC–CPG2, which is bioactive and with lower immunogenicity in ligand-directed enzyme prodrug therapy for cancer treatment.

Structures, electronic and magnetic properties of transition metals-doped Mg9O9 tubular clusters

The structures, electronic and magnetic attributes of the transition metal (TM) doping Mg9O9 tubular clusters have been investigated using the PBE functional. The results display that the ScMg9O9 and NiMg9O9 clusters are more structurally stable than the other TMMg9O9 clusters. An Sc atom replaces the Mg atom at the edge site of the Mg9O9 clusters, which leads to the Mg atom transferring to the top of an adjacent O atom. Ni atom prefers to occupy the bridge site of the Mg–O bond at a side of the Mg9O9 clusters. VMg9O9 and FeMg9O9 display more kinetic activity than the other TMMg9O9 clusters. The TM atoms lost certain electrons except for Co, Cu and Zn. The maximum spin value of the TM atoms for the ground-state TMMg9O9 clusters occurs at Mn.

Structures and electronic properties of the transition metal-adsorbed B36 clusters

Metal doping is considered as an effective method to stabilize the structures and optimize the properties of boron clusters. The structures and electronic properties of the [Formula: see text] clusters have been calculated at the Perdew–Burkle–Ernzerhof (PBE) level. The results reveal that the Cu atoms for the [Formula: see text] clusters unexpectedly enter the [Formula: see text] clusters. Ti, V, Co, Ni, Zr, Hf, Ta and W can obviously increase the structural stability of pristine [Formula: see text] clusters. The Ti, Cr, Fe, Ni and Zn; Y, Ru and Ag; Lu, Ta, Ir and Au-adsorbed [Formula: see text] clusters display higher kinetic activity than other [Formula: see text] clusters. The d orbital electrons of the TM atoms will significantly affect the distributions of the highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) states of pristine [Formula: see text] clusters. All the TM–B bonds of the [Formula: see text] clusters display covalent characters.