Purification of glucose 6-phosphate dehydrogenase from chicken erythrocytes. investigation of some kinetic properties

Glucose 6-phosphate dehydrogenase (G6PD) was purified from chicken erythrocytes, and some characteristics of the enzyme were investigated. The purification procedure was composed of three steps: hemolysate preparation, ammonium sulfate precipitation, and 2',5'-ADP Sepharose 4B affinity gel chromatography. Thanks to the three consecutive procedures, the enzyme, having the specific activity of 20.862 EU/mg proteins, was purified with a yield of 54.68% and 9,150-fold. Optimal pH, stable pH, optimal temperature, molecular weight, and KM and Vmax values for NADP+ and glucose 6- phosphate (G6-P) were also determined for the enzyme. In addition, Ki values and the type of inhibition were determined by means of Line-Weaver-Burk graphs obtained for such inhibitors as ATP, ADP, NADH, and NADPH.     

Overexpression of amyloid beta precursor protein enhances expression and secretion of ST6Gal1 in C2C12 myogenic cell line

The Abeta (amyloid‐beta) peptide is derived from the sequential cleavage of AbetaPP (amyloid‐beta precursor protein) by two enzymes, the β‐ and γ‐secretases. The major β‐secretase, identified as the novel transmembrane aspartic protease BACE1 (beta site APP‐cleaving enzyme 1), mediates the primary amyloidogenic cleavage of AbetaPP and initiates the production of Abeta. It has been implicated in the proteolytic processing of another substrate, namely ST6Gal1 (β galactoside α2,6‐sialyltransferase 1), which is the major α2,6‐sialyltransferase responsible for the broad synthesis of glycoproteins and glycolipids. The present study investigated the effect of overexpression of AbetaPP on expression and secretion of ST6Gal1 in skeletal muscle cells by inducing overexpression of wild‐type full‐length 751‐AbetaPP in the mouse myogenic cell line C2C12. Expression and secretion of the ST6Gal1 enzyme were analysed by Western blot and/or immunofluorescence staining. The results of our study demonstrated that AbetaPP overexpression in C2C12 cells increased the expression and the secretion of ST6Gal1 enzyme in vitro.     

Discovery of potent carbonic anhydrase,acetylcholinesterase, and butyrylcholinesterase enzymes inhibitors: The new amides and thiazolidine‐4‐ones synthesized on an acetophenone base

Compounds containing nitrogen and sulfur atoms can be widely used in various fields, including industry, medicine, biotechnology, and chemical technology. Among them, amides of acids and heterocyclic compounds have an important place. These amides and thiazolidine‐4‐ones showed good inhibitory action against butyrylcholinesterase (BChE), acetylcholinesterase (AChE), and human carbonic anhydrase isoforms. AChE exists at high concentrations in the brain and red blood cells. BChE is an important enzyme that is plentiful in the liver, and it is released into the blood in a soluble form. They were demonstrated to have effective inhibition profiles with K_i values of 23.76–102.75 nM against hCA I, 58.92–136.64 nM against hCA II, 1.40–12.86 nM against AChE, and 9.82–52.77 nM against BChE. On the other hand, acetazolamide showed K_i value of 482.63 ± 56.20 nM against hCA I, and 1019.60 ± 163.70 nM against hCA II. Additionally, Tacrine inhibited AChE and BChE, showing K_i values of 397.03 ± 31.66 and 210.21 ± 15.98 nM, respectively.     

Assessment of the inhibitory effects and molecular docking of some sulfonamides on human serum paraoxonase 1

Paraoxonase‐1 (PON1) is an organophosphate hydrolyzer and antiatherogenic enzyme. Due to the PON1's crucial functions, inhibitors and activators of PON1 must be known for pharmacological applications. In this study, we investigated the in vitro effects of some sulfonamides compounds on human serum PON1 (hPON1). For this aim, we purified the hPON1 from human serum with high specific activity by using simple chromatographic methods, and after the purification processes, we investigated in vitro interactions between the enzyme and some sulfonamides (2‐amino‐5‐methyl‐1,3‐benzenedisulfonamide, 2‐chloro‐4‐sülfamoilaniline, 4‐amino‐3‐methylbenzenesulfanilamide, sulfisoxazole, sulfisomidine, and 5‐amino‐2‐methylbenzenesulfonamide). IC₅₀, K_i values, and inhibition types were calculated for each sulfonamide. 2‐amino‐5‐methyl‐1,3‐benzenedisulfonamide and 2‐chloro‐4‐sülfamoilaniline exhibited noncompetitive inhibition effect, whereas 4‐amino‐3‐methylbenzenesulfanilamide, sulfisoxazole, and sulfisomidine exhibited mixed type inhibition. On the other hand, 5‐amino‐2‐methylbenzenesulfonamide showed competitive inhibition and so molecular docking studies were performed for this compound in order to assess the probable binding mechanism into the active site of hPON1.     

Cytoglobin inhibits migration through PI3K/AKT/mTOR pathway in fibroblast cells

Cell proliferation and migration are crucial in many physiological processes including development, cancer, tissue repair, and wound healing. Cell migration is regulated by several signaling molecules. Identification of genes related to cell migration is required to understand molecular mechanism of non-healing chronic wounds which is a major concern in clinics. In the current study, the role of cytoglobin (CYGB) gene in f?broblast cell migration and proliferation was described. L929 mouse fibroblast cells were transduced with lentiviral particles for CYGB and GFP, and analyzed for cell proliferation and migration ability. Fibroblast cells overexpressing CYGB displayed decreased cell proliferation, colony formation capacity, and cell migration. Phosphorylation levels of mTOR and two downstream effectors S6 and 4E-BP1 which take part in PI3K/AKT/mTOR signaling declined in CYGB-overexpressing cells. Microarray analysis indicated that CYGB overexpression leads to downregulation of cell proliferation, migration, and tumor growth associated genes in L929 cell line. This study demonstrated the role of CYGB in fibroblast cell motility and proliferation. CYGB could be a promising candidate for further studies as a potential target for diseases related to cell migration such as cancer and chronic wound treatment.     

Potent Inhibitory Effects of Some Phenolic Acids on Lactoperoxidase

Lactoperoxidase (LPO) plays a key role in immune response against pathogens. In this study, we examined the effects of some phenolic acids on LPO. For this purpose, bovine milk LPO was purified 380.85‐fold with a specific activity of 26.66 EU/mg and overall yield of 73.33% by using Amberlite CG‐50 H⁺ resin and CNBr‐activated Sepharose‐4B‐l ‐tyrosine‐sulfanilamide affinity chromatography. After purification, the in vitro effects of phenolic acids (tannic acid, 3,4‐dihydroxybenzoic acid, 3,5‐ dihydroxybenzoic acid, chlorogenic acid, sinapic acid, 4‐hydroxybenzoic acid, vanillic acid, salicylic acid, and 3‐hydroxybenzoic acid) were investigated on LPO. These phenolic acids showed potent inhibitory effect on LPO. K_i values for these phenolic acids were found as 0.0129 nM, 0.132 μM, 0.225 μM, 0.286 μM, 0.333 μM, 2.33 μM, 10.82 μM, 0.076 mM, and 0.405 mM, respectively. Sinapic acid and 4‐hydroxybenzoic acid exhibited noncompetitive inhibition; 3,4‐dihydroxybenzoic acid showed uncompetitive inhibition, and other phenolic acids showed competitive inhibition.     

Similarities and differences of hyperbaric oxygen and medical ozone applications

Hyperbaric oxygen (HBO) treatment is based on the principle of having the patient breath 100% oxygen in an environment above atmospheric pressure. Ozone (O(3)) is a colourless gas with a specific odour and consists of three oxygen atoms. The classical scientific understanding is that the world has become a place suitable for life for aerobic organisms with the increasing oxygen in the atmosphere billions of years ago. The formation of ozone after oxygen has then protected aerobic creatures from harmful rays. We now use these two gases for treatment purposes. It is noteworthy that the oxygen and ozone molecules that are formed by the same atom in different numbers are used for similar medical indications. We will try to emphasize the similarities and differences of HBO and medical ozone applications in this article.     

Translocation of Activator of G-protein Signaling 3 to the Golgi Apparatus in Response to Receptor Activation and Its Effect on the trans-Golgi Network

Group II activators of G-protein signaling play diverse functional roles through their interaction with Gα_i, Gα_t, and Gα_o via a G-protein regulatory (GPR) motif that serves as a docking site for Gα-GDP. We recently reported the regulation of the AGS3-Gα_i signaling module by a cell surface, seven-transmembrane receptor. Upon receptor activation, AGS3 reversibly dissociates from the cell cortex, suggesting that it may function as a signal transducer with downstream signaling implications, and this question is addressed in the current report. In HEK-293 and COS-7 cells expressing the α_2A/D-AR and Gα_i3, receptor activation resulted in the translocation of endogenous AGS3 and AGS3-GFP from the cell cortex to a juxtanuclear region, where it co-localized with markers of the Golgi apparatus (GA). The agonist-induced translocation of AGS3 was reversed by the α₂-AR antagonist rauwolscine. The TPR domain of AGS3 was required for agonist-induced translocation of AGS3 from the cell cortex to the GA, and the translocation was blocked by pertussis toxin pretreatment or by the phospholipase Cβ inhibitor {"type":"entrez-nucleotide","attrs":{"text":"U73122","term_id":"4098075","term_text":"U73122"}}U73122. Agonist-induced translocation of AGS3 to the GA altered the functional organization and protein sorting at the trans-Golgi network. The regulated movement of AGS3 between the cell cortex and the GA offers unexpected mechanisms for modulating protein secretion and/or endosome recycling events at the trans-Golgi network.     

Shoot proliferation and HPLC-determination of iridoid glycosides in clones of <Emphasis Type="Italic">Gentiana cruciata</Emphasis> L

Gentiana cruciata L. (Cross gentian) is a medicinal and ornamental plant, threatened in its natural habitats. The wild root extracts of this species are known to exhibit many curative properties. In the present study, an efficient protocol for in vitro propagation of G. cruciata L. was developed from node culture. A semi-solidified Murashige and Skoog (MS) basal medium supplemented with 2.22 μM 6-benzyladenine (BA), 2.46 μM indole-3-butyric acid (IBA) and sucrose (3% w/v) improved the production of multiple shoots directly from nodal segments, providing 3.9 shoots per explants on average. The highest rooting (81.7%) was observed with half-strength MS medium supplemented with 2.46 μM IBA. Plants with well-developed roots were transferred to pots containing turf/vermiculite mixtures and acclimatized in plant growth chamber conditions. Acclimatized plants showed 100% survival and remained healthy. The content of secondary metabolites in the clones was determined by HPLC, and the presence of gentiopicroside, loganic acid, swertiamarin, and sweroside in the samples was confirmed. Gentiopicroside was found to be the major compound.