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91.
Cambon-Bonavita MA Schmitt P Zieger M Flaman JM Lesongeur F Raguénès G Bindel D Frisch N Lakkis Z Dupret D Barbier G Quérellou J 《Extremophiles : life under extreme conditions》2000,4(4):215-225
The DNA polymerase I gene of a newly described deep-sea hydrothermal vent Archaea species, Thermococcus fumicolans, from IFREMERS's collection of hyperthermophiles has been cloned in Escherichia coli. As in Thermococcus litoralis, the gene is split by two intervening sequences (IVS) encoding inteins inserted in sites A and C of family B DNA polymerases.
The entire DNA polymerase gene, containing both inteins, was expressed at 30°C in E. coli strain BL21(DE3)pLysS using the pARHS2 expression vector. The native polypeptide precursor of 170 kDa was obtained, and intein
splicing as well as ligation of the three exteins was observed in vitro after heat exposure. The recombinant enzyme was purified
and some of its activities were characterized: polymerization, thermostability, exonuclease activities, and fidelity.
Received: September 17, 1999 / Accepted: March 21, 2000 相似文献
92.
The α-subunit of both the human heart (hH1) and human skeletal muscle (hSkM1) sodium channels were expressed in a mammalian
expression system. The channels displayed slow (hH1) and fast (hSkM1) current decay kinetics similar to those seen in native
tissues. Hence, the aim of this study was to identify the region on the α-subunit involved in the differences of these current-decay
kinetics. A series of hH1/hSkM1 chimeric sodium channels were constructed with the focus on the C-terminal region. Sodium
currents of chimeric channels were recorded using the patch-clamp technique in whole-cell configuration. Chimeras where the
C-terminal region had been exchanged between hH1 and hSkM1 revealed that this region contains the elements that cause differences
in current decay kinetics between these sodium channel isoforms. Other biophysical characteristics (steady-state activation
and inactivation and recovery from inactivation) were similar to the phenotype of the parent channel. This indicates that
the C-terminus is exclusively implicated in the differences of current decay kinetics. Several other chimeras were constructed
to identify a specific region of the C-terminus causing this difference. Our results showed that the first 100-amino-acid
stretch of the C-terminal region contains constituents that could cause the differences in current decay between the heart
and skeletal muscle sodium channels.
This study has uncovered a direct relationship between the C-terminal region and the current-decay of sodium channels. These
findings support the premise that a novel regulatory component exists for fast inactivation of voltage-gated sodium channels.
Received: 1 March 2001/Revised: 18 May 2001 相似文献
93.
Asma Mohammadi Ali Reza Balizadeh Karami Vahid Dehghan Mashtani Tooba Sahraei Zeinab Bandani Tarashoki Ehsan Khattavian Sara Mobarak Hossein Moradi Kazerouni Esmat Radmanesh 《Reports of Biochemistry & Molecular Biology》2021,10(2):183
Background:MicroRNA expression signature and reactive oxygen species (ROS) production have been associated with the development of cardiovascular diseases (CVDs). This study aimed to evaluate oxidative stress, inflammation, apoptosis, and the expression of miRNA-208a and miRNA-1 in cardiovascular patients.Methods:The study population included four types of patients (acute coronary syndromes (ACS), myocardial infarction (MI), arrhythmia, and heart failure (HF)), with 10 people in each group, as well as a control group. Quantitative real-time PCR was performed to measure mir-208 and miR-1 expression, the mRNAs of inflammatory mediators (TNFα, iNOS/eNOS), and apoptotic factors (Bax and Bcl2). XOX, MDA, and antioxidant enzymes (CAT, SOD, and GPx) were measured by ZellBio GmbH kits by an ELISA Reader.Results:The results showed significant decreases in the activity of antioxidant enzymes (CAT, SOD, and Gpx) and a significant increase in the activity of the MDA and XOX in cardiovascular patients. Significant increases in IL-10, iNos, iNOS / eNOS, and TNF-α in cardiovascular patients were also observed. Also, a significant increase in the expression of miR-208 (HF> arrhythmia> ACS> MI) and a significant decrease in the expression of miR-1 (ACS> arrhythmia> HF> MI) were found in all four groups in cardiovascular patients.Conclusion:The results showed increases in oxidative stress, inflammation, apoptotic factors, and in the expression of miR-208a in a variety of cardiovascular patients (ACS, MI, arrhythmia, and HF). It is suggested that future studies determine the relationships that miR-1, miR-208, and oxidative stress indices have with inflammation and apoptosis.Key Words: Apoptosis, Cardiovascular diseases, Inflammation, microRNA-208a, microRNA-1, Oxidative stress 相似文献
94.
95.
Azarmehr Zahra Ranji Najmeh Khazaei Koohpar Zeinab Habibollahi Hadi 《Molecular biology reports》2021,48(3):2533-2542
Molecular Biology Reports - The aim of this study was to consider the expression of farnesoid X receptor (Fxr), liver X receptor (LXRα) and sirtuin 1 (Sirt1), oxidative stress, inflammation,... 相似文献
96.
97.
Abedien Zabardasti Ali Kakanejadi Fatemeh Ghenaatian Zeinab Bigleri 《Molecular simulation》2013,39(12):960-968
Ab initio and density functional calculations are used to analyse the interaction between a molecule of the cyanuric acid and one, two and three molecules of water at B3LYP/6-311++ G(d,p) and MP2/6-311++ G(d,p) computational levels. Also, the cooperative effect (CE) in terms of the stabilisation energy of clusters is calculated and discussed. Depending on the geometry of clusters under study, the cooperative, non- or anti-CE was found with an increasing cluster size. Red shifts of N–H and C = O stretching frequencies illustrate a good dependence on the CE. The atoms in molecules theory is used to analyse the CE on topological parameters. 相似文献
98.
Shams Nemat Shakarami Gandabeh Zeinab Nazifi Narges Forouharmehr Ali Jaydari Amin Rashidian Ehsan 《International journal of peptide research and therapeutics》2020,26(3):1527-1539
International Journal of Peptide Research and Therapeutics - Salmonella is a gram-negative bacterium belonging to the Enterobacteriaceae family. One of the major known serotypes of this bacterium... 相似文献
99.
Mohamed TM Oceandy D Zi M Prehar S Alatwi N Wang Y Shaheen MA Abou-Leisa R Schelcher C Hegab Z Baudoin F Emerson M Mamas M Di Benedetto G Zaccolo M Lei M Cartwright EJ Neyses L 《The Journal of biological chemistry》2011,286(48):41520-41529
Identification of the signaling pathways that regulate cyclic nucleotide microdomains is essential to our understanding of cardiac physiology and pathophysiology. Although there is growing evidence that the plasma membrane Ca(2+)/calmodulin-dependent ATPase 4 (PMCA4) is a regulator of neuronal nitric-oxide synthase, the physiological consequence of this regulation is unclear. We therefore tested the hypothesis that PMCA4 has a key structural role in tethering neuronal nitric-oxide synthase to a highly compartmentalized domain in the cardiac cell membrane. This structural role has functional consequences on cAMP and cGMP signaling in a PMCA4-governed microdomain, which ultimately regulates cardiac contractility. In vivo contractility and calcium amplitude were increased in PMCA4 knock-out animals (PMCA4(-/-)) with no change in diastolic relaxation or the rate of calcium decay, showing that PMCA4 has a function distinct from beat-to-beat calcium transport. Surprisingly, in PMCA4(-/-), over 36% of membrane-associated neuronal nitric-oxide synthase (nNOS) protein and activity was delocalized to the cytosol with no change in total nNOS protein, resulting in a significant decrease in microdomain cGMP, which in turn led to a significant elevation in local cAMP levels through a decrease in PDE2 activity (measured by FRET-based sensors). This resulted in increased L-type calcium channel activity and ryanodine receptor phosphorylation and hence increased contractility. In the heart, in addition to subsarcolemmal calcium transport, PMCA4 acts as a structural molecule that maintains the spatial and functional integrity of the nNOS signaling complex in a defined microdomain. This has profound consequences for the regulation of local cyclic nucleotide and hence cardiac β-adrenergic signaling. 相似文献
100.
Al-Khalifa A Maddaford TG Chahine MN Austria JA Edel AL Richard MN Ander BP Gavel N Kopilas M Ganguly R Ganguly PK Pierce GN 《American journal of physiology. Regulatory, integrative and comparative physiology》2007,292(3):R1198-R1203
Polyunsaturated fatty acids (PUFAs) have significant, cardioprotective effects against ischemia. Hempseed contains a high proportion of the PUFAs linoleic acid (LA) and alpha-linolenic acid (ALA), which may have opposing effects on postischemic heart performance. There are no reported data concerning the cardiovascular effects of dietary hempseed intake. A group of 40 male Sprague-Dawley rats were distributed evenly into four groups that were fed for 12 wk a normal rat chow supplemented with hempseed (5% and 10%), palm oil (1%), or a 10% partially delipidated hempseed that served as a control. Plasma ALA and gamma-linolenic acid levels were significantly elevated in the rats that were fed a 5% or 10% hempseed-supplemented diet, but in heart tissue only ALA levels were significantly elevated in the rats fed these diets compared with control. After the dietary interventions were completed, postischemic heart performance was evaluated by measuring developed tension, resting tension, the rates of tension development and relaxation, and the number of extrasystoles. Hearts from rats fed a hempseed-supplemented diet exhibited significantly better postischemic recovery of maximal contractile function and enhanced rates of tension development and relaxation during reperfusion than hearts from the other groups. These hearts, however, were not protected from the occurrence of extrasystoles, nor were the increases in resting tension altered during ischemia or reperfusion as a function of any dietary intervention. Our data demonstrate that dietary hempseed can provide significant cardioprotective effects during postischemic reperfusion. This appears to be due to its highly enriched PUFA content. 相似文献