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1.
Tahere Kondori Khatereh Abdi Michal Dušek Václav Eigner 《Journal of biomolecular structure & dynamics》2020,38(1):236-247
AbstractA mononuclear cadmium(II) complex of formula [Cd(5,5′-dmbipy)2(OAc)2]·2H2O (5,5′-dmbipy = 5,5′-dimethyl-2,2′-bipyridine and OAc?=?acetato ligand) has been synthesized and characterized by FT-IR, UV–Vis, 1H-NMR, elemental analysis and single-crystal X-ray structure analysis. The molecular structure of the complex shows a distorted tetragonal antiprism CdN4O4 coordination geometry around the cadmium atom, resulting in coordination by four nitrogen atoms from two 5,5′-dmbipy ligands and four oxygen atoms from two acetate anions. The interaction of this complex to FS-DNA (fish sperm DNA) has also been studied by electronic absorption, fluorescence and gel electrophoresis techniques. Binding constant (Kb), Stern–Volmer constant (Ksv), number of binding sites (n) and bimolecular quenching rate constant (kq) have been calculated from these spectroscopic data. These results have revealed that the metal complex can bind effectively to FS-DNA via groove binding. The calculated thermodynamic parameters (ΔH°, ΔS° and ΔG°) show that hydrogen bonding and van der Waals forces have an important function in the Cd(II) complex–DNA interaction. The antibacterial effects of the synthesized cadmium complex have also been examined in vitro against standard bacterial strains: one Gram-positive (Staphylococcus aureus, ATCC 25923) and one Gram-negative (Escherichia coli, ATCC 25922) bacteria, using disk diffusion and macro-dilution broth methods. The obtained results show that the Cd(II) complex exhibits a marked antibacterial activity which is significantly better than those observed for its free ligand and metal salt for both Gram-positive and Gram-negative bacteria. However, this metal complex is a more potent antibacterial agent against the Gram-positive than that of the Gram-negative bacteria.Communicated by Ramaswamy H. Sarma 相似文献
2.
Abdollahi M Bahreini-Moghadam A Emami B Fooladian F Zafari K 《Comparative biochemistry and physiology. Toxicology & pharmacology : CBP》2003,135(3):331-336
The effect of cadmium on induction of oxidative stress in rat submandibular saliva and protective role of increasing intracellular cAMP and cGMP by use of specific phosphodiesterase inhibitors, theophylline and sildenafil were investigated. Pure submandibular saliva was collected intraorally by micro polyethylene cannula from anaesthetized rats using pilocarpine as secretagogue. Acute administration of cadmium (10 mg/kg) caused significant oxidative stress by increasing lipid peroxidation by-products (thiobarbituric reactive substances, TBARS) and decreasing total thiols and total antioxidant power of the saliva. Concurrent therapy of rats by theophylline (25 mg/kg) and sildenafil (5 mg/kg) prevented cadmium-induced oxidative stress in saliva. Theophylline and sildenafil inhibited cadmium-induced increase in lipid peroxidation and decrease in total thiols and antioxidant power. It is concluded that cadmium administration results in oxidative stress in rat submandibular saliva, which can be protected by concurrent administration of specific cyclic nucleotide phosphodiesterase inhibitors. 相似文献
3.
Proteolysis of the membrane type-1 matrix metalloproteinase prodomain: implications for a two-step proteolytic processing and activation 总被引:1,自引:0,他引:1
Golubkov VS Chekanov AV Shiryaev SA Aleshin AE Ratnikov BI Gawlik K Radichev I Motamedchaboki K Smith JW Strongin AY 《The Journal of biological chemistry》2007,282(50):36283-36291
Membrane type-1 matrix metalloproteinase (MT1-MMP) exerts its enhanced activity in multiple cancer types. Understanding the activation process of MT1-MMP is essential for designing novel and effective cancer therapies. Like all of the other MMPs, MT1-MMP is synthesized as a zymogen, the latency of which is maintained by its inhibitory prodomain. Proteolytic processing of the prodomain transforms the zymogen into a catalytically active enzyme. A sequential, two-step activation process is normally required for MMPs. Our in silico modeling suggests that the prodomain of MT1-MMP exhibits a conserved three helix-bundled structure and a "bait" loop region linking helixes 1 and 2. We hypothesized and then confirmed that in addition to furin cleavage there is also a cleavage at the bait region in the activation process of MT1-MMP. A two-step sequential activation of MT1-MMP is likely to include the MMP-dependent cleavage at either P47GD downward arrowL50 or P58QS downward arrowL61 or at both sites of the bait region. This event results in the activation intermediate. The activation process is then completed by a proprotein convertase cleaving the inhibitory prodomain at the R108RKR111 downward arrowY112 site, where Tyr112 is the N-terminal residue of the mature MT1-MMP enzyme. Our findings suggest that the most efficient activation results from a two-step mechanism that eventually is required for the degradation of the inhibitory prodomain and the release of the activated, mature MT1-MMP enzyme. These findings shed more light on the functional role of the inhibitory prodomain and on the proteolytic control of MT1-MMP activation, a crucial process that may be differentially regulated in normal and cancer cells. 相似文献
4.
Light causes phosphorylation of nonactivated visual pigments in intact mouse rod photoreceptor cells
Shi GW Chen J Concepcion F Motamedchaboki K Marjoram P Langen R Chen J 《The Journal of biological chemistry》2005,280(50):41184-41191
Phosphorylation of G-protein-coupled receptors (GPCRs) is a required step in signal deactivation. Rhodopsin, a prototypical GPCR, exhibits high gain phosphorylation in vitro whereby a hundred-fold molar excess of phosphates are incorporated into the rhodopsin pool per molecule of activated rhodopsin. The extent by which high gain phosphorylation occurs in the intact mammalian photoreceptor cell, and the molecular mechanism underlying this reaction in vivo, is not known. Trans-phosphorylation is a mechanism proposed for high gain phosphorylation, whereby rhodopsin kinase, upon phosphorylating the activated receptor, continues to phosphorylate nearby nonactivated rhodopsin. We used two different transgenic mouse models to test whether trans-phosphorylation occurs in the intact photoreceptor cell. The first transgenic model expressed a murine cone pigment, S-opsin, together with the endogenous rhodopsin in the rod cell. We showed that selective stimulation of rhodopsin also led to phosphorylation of S-opsin. The second mouse model expressed the constitutively active human opsin mutant K296E. K296E, in the arrestin-/- background, also led to phosphorylation of endogenous mouse rhodopsin in the dark-adapted retina. Both mouse models provide strong support of trans-phosphorylation as an underlying mechanism of high gain phosphorylation, and provide evidence that a substantial fraction of nonactivated visual pigments becomes phosphorylated through this mechanism. Because activated, phosphorylated receptors exhibit decreased catalytic activity, our results suggest that dephosphorylation would be an important step in the full recovery of visual sensitivity during dark adaptation. These results may also have implications for other GPCR signaling pathways. 相似文献
5.
Vladislav S. Golubkov Piotr Cieplak Alexei V. Chekanov Boris I. Ratnikov Alexander E. Aleshin Natalya V. Golubkova Tatiana I. Postnova Ilian A. Radichev Dmitri V. Rozanov Wenhong Zhu Khatereh Motamedchaboki Alex Y. Strongin 《The Journal of biological chemistry》2010,285(36):27726-27736
The functional activity of invasion-promoting membrane type 1 matrix metalloproteinase (MT1-MMP) is elevated in cancer. This elevated activity promotes cancer cell migration, invasion, and metastasis. MT1-MMP is synthesized as a zymogen, the latency of which is maintained by its prodomain. Excision by furin was considered sufficient for the prodomain release and MT1-MMP activation. We determined, however, that the full-length intact prodomain released by furin alone is a potent autoinhibitor of MT1-MMP. Additional MMP cleavages within the prodomain sequence are required to release the MT1-MMP enzyme activity. Using mutagenesis of the prodomain sequence and mass spectrometry analysis of the prodomain fragments, we demonstrated that the intradomain cleavage of the PGD↓L50 site initiates the MT1-MMP activation, whereas the 108RRKR111↓Y112 cleavage by furin completes the removal and the degradation of the autoinhibitory prodomain and the liberation of the functional activity of the emerging enzyme of MT1-MMP. 相似文献
6.
Micelle/water mixed solutions of different surface active agents were studied for their effectiveness in the extraction of polyphenolic compounds from various varieties of apples from west Azerbaijan province in Iran. The total content of polyphenolic compound in fruit extracts were determined using ferrous tartrate and Folin–Ciocalteu assays methods and chromatographic methods and compared with theme. High performance liquid chromatography is one of the most common and important methods in biochemical compound identification. The effect of pH, ionic strength, surfactant type, surfactant concentration, extraction time and common organic solvent in the apple polyphenolics extractions was studied using HPLC-DAD. Mixtures of surfactants, water and methanol at various ratios were examined and micellar-water solutions of Brij surfactant showed the highest polyphenol extraction efficiency. Optimum conditions for the extraction of polyphenolic compounds from apple occurred at 7 mM Brij35, pH 3. Effect of ionic strength on extraction was determined and 2% (W/V) potassium Chloride was determined to be the optimum salt concentration. The procedure worked well with an ultrasound bath. Total antioxidant capacity also was determined in this study. The method can be safely scaled up for pharmaceutical applications. 相似文献
7.
Khatereh Saei Arezoumand Effat Alizadeh Mohammad Esmaeillou Maryam Ghasemi Shahriar Alipour Younes Pilehvar-Soltanahmadi Nosratollah Zarghami 《In vitro cellular & developmental biology. Animal》2018,54(3):205-216
In recent decades, mesenchymal stem cells originated from adipose tissue (adipose-derived stem cells, ASCs) have gained increased attention for production of cell-based therapeutics. Emu oil as a natural compound showed antioxidant effects in previous studies. The goal of this study was to investigate the effect of crude emu oil on the proliferation, cell cycle progression, stemness genes expression, and in vitro wound healing potential of ASCs. An emulsion of emu oil was prepared using egg lecithin and butylated hydroxytoluene to improve bioavailability and solubility of emu oil in the expansion medium. The ASCs were treated using a series of emu oil concentrations in emulsion form, diluted in expansion medium (0.03–3 mg/ml). The emu oil-free emulsion was used as control treatment. The results revealed that emu oil (1.25 mg/ml) in emulsion form significantly (p?<?0.001) increased ASCs proliferation and colony formation. Additionally, emu oil caused upregulation of stemness marker genes (Sox2, Oct4, Nanog, and Nestin) (p?<?0.05). The cell cycle analysis after emu oil treatments showed an increase in the population of ASCs in S-phase of the cell cycle. Besides, an accelerated in vitro scratch wound healing was observed in emu oil-treated ASCs. Emu oil enhanced proliferation, colony formation, stemness genes expression, and in vitro wound healing of ASCs. These findings suggest that emu oil treatment could maintain the stemness of ex vivo cultivated ASCs and enhance their regenerative potential. 相似文献
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9.
Sergey A. Shiryaev Albert G. Remacle Alexei Y. Savinov Andrei V. Chernov Piotr Cieplak Ilian A. Radichev Roy Williams Tatiana N. Shiryaeva Katarzyna Gawlik Tatiana I. Postnova Boris I. Ratnikov Alexei M. Eroshkin Khatereh Motamedchaboki Jeffrey W. Smith Alex Y. Strongin 《The Journal of biological chemistry》2009,284(44):30615-30626
10.
Reza Mohammadrezaei Khorramabadi Khatereh Anbari Mohammad Reza Salahshoor Masoud Alasvand Vahideh Assadollahi Mohammadreza Gholami 《Journal of cellular physiology》2020,235(12):9876-9883
Quercetin, an antioxidant derived from plants, can play a beneficial role in the protection of various tissues against ischemia-reperfusion injuries (IRI). The purpose of the present research was to investigate the protective effects of quercetin on gastrocnemius muscle ischemia-reperfusion. A total of 80 adult male Wistar rats (weights: 250–300 g) were divided into ten groups (n = 8 per group). We used silk 6.0 surgical thread to create a knit to occlude the femoral artery and vein for 3 hr. The treated groups, which comprised half of each experimental group, received intraperitoneal injections of 150 mg/kg quercetin after the ischemia. Blood flow was subsequently reestablished in the reperfusion phase. The rats were kept in reperfusion for 3, 7, 14, or 28 days after which they were killed with high doses of anesthetic drugs, and the gastrocnemius muscles were removed and fixed. Tissue processing, hematoxylin and eosin and toluidine blue staining, and immunohistochemistry were used to assess tumor necrosis factor-α (TNF-α) and nuclear factor κB (NF-κB) levels. A comparison between treated and untreated ischemic sites showed that on the third day of reperfusion, the severity of edema and NF-κB level decreased significantly; on the 7th day of reperfusion, the severity of edema and the levels of TNF-α and NF-κB decreased significantly; and on the 14th day of reperfusion, all of the parameters showed significant decreases. On the 28th day of reperfusion, there were significantly decreased levels of TNF-α and NF-κB, and decreased mast cell infiltration when compared with the untreated groups. According to the results, administration of quercetin after ischemia could significantly prevent gastrocnemius muscle IRI. 相似文献