Receptors & channels最新文献_第5页

A Novel Kind of G Protein Heterodimer: The Gβ5-RGS Complex 一种新型G蛋白异二聚体:Gβ5- rgs复合物

Receptors & channels Pub Date : 2003-01-01 DOI: 10.1080/10606820308239

D. Witherow, V. Slepak

引用次数: 43

High throughput electrophysiology using a fully automated, multiplexed recording system. 高通量电生理使用全自动，多路记录系统。

Receptors & channels Pub Date : 2003-01-01 DOI: 10.3109/10606820308252

J. D. Trumbull, E. Maslana, D. Mckenna, Thomas A. Nemcek, W. Niforatos, Jeffrey Y. Pan, A. Parihar, C. Shieh, Julie A. Wilkins, C. Briggs, D. Bertrand

{"title":"High throughput electrophysiology using a fully automated, multiplexed recording system.","authors":"J. D. Trumbull, E. Maslana, D. Mckenna, Thomas A. Nemcek, W. Niforatos, Jeffrey Y. Pan, A. Parihar, C. Shieh, Julie A. Wilkins, C. Briggs, D. Bertrand","doi":"10.3109/10606820308252","DOIUrl":"https://doi.org/10.3109/10606820308252","url":null,"abstract":"The drug discovery process centers around finding and optimizing novel compounds active at therapeutic targets. This process involves direct and indirect measures of how compounds affect the behavior of the target in question. The sheer number of compounds that must be tested poses problems for classes of ion channel targets for which direct functional measurements (e.g., traditional patch-clamping) are too cumbersome and indirect measurements (e.g., Ca(2+)-sensitive dyes) lack sufficient sensitivity or require unacceptable compromises. We present an optimized process for obtaining large numbers of direct electrophysiological measurements (two-electrode voltage-clamp) from Xenopus oocytes using a combination of automated oocyte handling, efficient and flexible liquid delivery, parallel operation, and powerful integrated data analysis. These improvements have had a marked impact, increasing the contribution electrophysiology makes in optimizing lead compound series and the discovery of new ones. The design of the system is detailed along with examples of data generated in support of lead optimization and discovery.","PeriodicalId":20928,"journal":{"name":"Receptors & channels","volume":"24 1","pages":"19-28"},"PeriodicalIF":0.0,"publicationDate":"2003-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89082530","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 14

A novel kind of G protein heterodimer: the G beta5-RGS complex. 一种新型G蛋白异二聚体：G β 5- rgs复合物。

Receptors & channels Pub Date : 2003-01-01

D Scott Witherow, Vladlen Z Slepak

引用次数: 0

Flip the tip: an automated, high quality, cost-effective patch clamp screen. 翻转提示:一个自动化，高品质，高性价比的膜片钳屏幕。

Receptors & channels Pub Date : 2003-01-01 DOI: 10.3109/10606820308257

A. Lepple-Wienhues, K. Ferlinz, Achim Seeger, A. Schäfer

引用次数: 58

Unaltered agonist potency upon inducible 5-HT7(a) but not 5-HT4(b) receptor expression indicates agonist-independent association of 5-HT7(a) receptor and Gs. 激动剂对诱导的5-HT7(a)而不是5-HT4(b)受体表达的效力不变，表明5-HT7(a)受体与Gs的关联不依赖于激动剂。

Receptors & channels Pub Date : 2003-01-01 DOI: 10.1080/10606820308245

S. Bruheim, K. Krobert, K. W. Andressen, F. Levy

{"title":"Unaltered agonist potency upon inducible 5-HT7(a) but not 5-HT4(b) receptor expression indicates agonist-independent association of 5-HT7(a) receptor and Gs.","authors":"S. Bruheim, K. Krobert, K. W. Andressen, F. Levy","doi":"10.1080/10606820308245","DOIUrl":"https://doi.org/10.1080/10606820308245","url":null,"abstract":"We compared adenylyl cyclase (AC) activation by the G protein-coupled human serotonin (5-HT) receptors 5-HT4(b) and 5-HT7(a) using an ecdysone-inducible expression system, which allowed for reproducible expression of increasing receptor densities in clonal HEK293 (EcR293) cell lines. Low constitutive expression of receptors (2-70 fmol/mg protein) was observed and could be titrated up to 50-200-fold (approximately 400-7000 fmol/mg protein) by the ecdysone analogue ponasterone A. Although 5-HT-stimulated AC activity increased with receptor density, interclonal variation precluded comparisons of coupling efficiency. Interestingly, the potency of 5-HT to stimulate AC increased with increasing receptor density only in clones expressing 5-HT4(b) receptors. The potency for 5-HT did not change in clones expressing 5-HT7(a) receptors, even though 5-HT-stimulated AC activity approached asymptotic levels. This indicates that potency of 5-HT for stimulation of AC through the 5-HT7(a) receptor is independent of receptor-Gs stoichiometry and is consistent with a model where the 5-HT7(a) receptors are tightly associated with G protein, independent of agonist binding. This supports the existence of a complex between inactive receptor and G protein, as predicted by the cubic ternary complex model. In such a system, spare receptors do not lead to increased potency of an agonist with increased receptor density.","PeriodicalId":20928,"journal":{"name":"Receptors & channels","volume":"52 1","pages":"107-16"},"PeriodicalIF":0.0,"publicationDate":"2003-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83268500","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 30

Upscaling and automation of electrophysiology: toward high throughput screening in ion channel drug discovery. 电生理学的升级和自动化:迈向离子通道药物发现的高通量筛选。

Receptors & channels Pub Date : 2003-01-01

Margit Asmild, Nicholas Oswald, Karen M Krzywkowski, Søren Friis, Rasmus B Jacobsen, Dirk Reuter, Rafael Taboryski, Jonathan Kutchinsky, Ras K Vestergaard, Rikke L Schrøder, Claus B Sørensen, Morten Bech, Mads P G Korsgaard, Niels J Willumsen

引用次数: 0

Proteinous amino acids in muscle cytosol of rats' heart after exercise and hypoxia. 运动和缺氧后大鼠心肌细胞质中蛋白质氨基酸的变化。

Receptors & channels Pub Date : 2003-01-01 DOI: 10.3109/713745178

Janusz Gabrys, Janusz Konecki, Jashovam Shani, Artur Durczok, Grzegorz Bielaczyc, Andrzej Kosteczko, Halina Szewczyk, Ryszard Brus

{"title":"Proteinous amino acids in muscle cytosol of rats' heart after exercise and hypoxia.","authors":"Janusz Gabrys, Janusz Konecki, Jashovam Shani, Artur Durczok, Grzegorz Bielaczyc, Andrzej Kosteczko, Halina Szewczyk, Ryszard Brus","doi":"10.3109/713745178","DOIUrl":"https://doi.org/10.3109/713745178","url":null,"abstract":"Levels of 19 proteinous amino acids and of total free amino acids were assayed by gas-liquid chromatography in cytosols of rat atrial and ventricular heart muscle cardiomyocytes. These amino acids were assayed after the rats had been exposed to either exercise (swimming) or hypoxia (hypobaric pressure of 686 hectoPascals). Out of the total free amino acids levels of arginine, glutamine and cysteine in atrial and ventricular cardiac muscle cytosols of control rats were the highest of all amino acids assayed. The control levels of all other amino acids assayed in atrial or ventricular cardiac muscles ranged from 0.1% to 10.6% of the total free amino acids in the control rats. Physical stress (exercise and hypoxia) significantly reduced the total amount of cytosolic free amino acids in both heart muscles. While hypoxia decreased the levels of arginine in both heart muscles, exercise abolished the level of cysteine in the atrial heart muscle. Decrease in arginine levels, and elimination of cysteine from the heart's atrial muscle after physical stress, may be attributed to its utilization of nitric oxide and to its synthesis of atriopeptin and/or endothelin during stress. No change was recorded in either experimental group in the level of glutamine in heart muscle cytosol. Exercise and hypoxia affect, in different modes, the levels of all other amino acids assayed, except for tryptophan, tyrosine, and histidine, which are precursors of endogenous neurotransmitters. The impact of proteinous amino acids on some bodily functions is discussed.","PeriodicalId":20928,"journal":{"name":"Receptors & channels","volume":"9 5","pages":"301-7"},"PeriodicalIF":0.0,"publicationDate":"2003-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.3109/713745178","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"24013766","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 5

A bifunctional alkylating nitrogen mustard agent that utilizes barbituric acid as carrier drug with the potential for crossing the brain-blood barrier. 一种双功能烷基化氮芥剂，利用巴比妥酸作为载体药物，具有穿越脑血屏障的潜力。

Receptors & channels Pub Date : 2003-01-01 DOI: 10.3109/713745173

Ronald Bartzatt, Laura Donigan

{"title":"A bifunctional alkylating nitrogen mustard agent that utilizes barbituric acid as carrier drug with the potential for crossing the brain-blood barrier.","authors":"Ronald Bartzatt, Laura Donigan","doi":"10.3109/713745173","DOIUrl":"https://doi.org/10.3109/713745173","url":null,"abstract":"Barbituric acid is the parent compound of a large family of hypnotic barbiturates. A nitrogen mustard (N-mustard) group (-CH2CH2N[CH2CH2Cl]2) was placed onto the two nitrogen atoms at positions 1 and 3 of the pyrimidine ring. This N-mustard agent is a solid at 25 degrees C, stable at -10 degrees C for >10 weeks, and soluble in aqueous solvent at 37 degrees C and 25 degrees C. The partition coefficients miLog P and CLog P were calculated to be -0.93 and -1.441 for barbituric acid. The miLog P and CLog P for the N-mustard agent were 1.82 and 2.707, respectively. The N-mustard substituents significantly increased solubility in lipid by-layers. The N-mustard agent alkylated a nucleophilic primary amine (p-chloroaniline) at physiological conditions of pH 7.4 and 37 degrees C. Aliquots of reaction mixtures were withdrawn at known time periods to react with fluorescamine for determination of unreacted p-chloroaniline and calculation of rate constants. The alkylation of the primary amine was second order with rate = k2[Nu]2, (Nu is nucleophile) and rate constant k2 = 0.01358 L/(mole.min). The molecular dipole of barbituric acid and the N-mustard agent was calculated by SPARTAN software (wavefunction, Irvine, CA) to be 0.681 and 2.153 Debye, respectively. The brain/blood partition coefficient (Log BB) of the N-mustard agent was -0.399. Values of molecular polar surface area (TPSA) for barbituric acid and the N-mustard agent was 75.27 and 64.17, respectively. TPSA values indicate an expected intestinal absorbance to be 79% and 90%, respectively. The N-mustard agent showed zero violations of the Rule of 5, indicating good bioavailability.","PeriodicalId":20928,"journal":{"name":"Receptors & channels","volume":"9 5","pages":"309-13"},"PeriodicalIF":0.0,"publicationDate":"2003-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.3109/713745173","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"24013767","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 2

Phylogenomic analysis and evolution of the potassium channel gene family. 钾通道基因家族的系统基因组分析与进化。

Receptors & channels Pub Date : 2003-01-01 DOI: 10.3109/714041017

G Moulton, T K Attwood, D J Parry-Smith, J C L Packer

引用次数: 23

Scanning mutagenesis studies of the M1 muscarinic acetylcholine receptor. M1毒蕈碱乙酰胆碱受体的扫描诱变研究。

Receptors & channels Pub Date : 2003-01-01 DOI: 10.1080/10606820308261

E. Hulme, Z. L. Lu, M. Bee

{"title":"Scanning mutagenesis studies of the M1 muscarinic acetylcholine receptor.","authors":"E. Hulme, Z. L. Lu, M. Bee","doi":"10.1080/10606820308261","DOIUrl":"https://doi.org/10.1080/10606820308261","url":null,"abstract":"Following the solution of the structure of bovine rhodopsin by X-ray crystallography, it has been possible to build an improved homology model of the M(1) muscarinic acetylcholine receptor. This has been used to interpret the outcome of an extensive series of scanning and point mutagenesis studies on the transmembrane domain of the receptor. Potential intramolecular interactions enhancing the stability of the protein fold have been identified. The residues contributing to the binding site for the antagonist, N-methylscopolamine, and the agonist, acetylcholine have been mapped. The positively charged headgroups of these ligands appear to bind in a charge-stabilized aromatic cage formed by amino acid side chains in transmembrane (TM) helices 3, 6, and 7, while residues in TM 4 may participate in a peripheral docking site. Closure of the cage around the headgroup of acetylcholine may help to transduce binding energy into receptor activation, possibly disrupting a set of Van der Waals interactions between a set of residues underlying the binding site which help to constrain the receptor to the inactive state, in the absence of agonist. This may trigger the reorganization of a hydrogen bonding network between highly conserved residues in the core of the receptor, whose integrity is crucial for activation.","PeriodicalId":20928,"journal":{"name":"Receptors & channels","volume":"41 1","pages":"215-28"},"PeriodicalIF":0.0,"publicationDate":"2003-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85254329","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 53