Radioligand Assay: Quantitative determination of receptor (binding) proteins in body fluids or tissue using radioactively labeled binding reagents (e.g., antibodies, intracellular receptors, plasma binders).Binding, Competitive: The interaction of two or more substrates or ligands with the same binding site. The displacement of one by the other is used in quantitative and selective affinity measurements.Dihydroalprenolol: Hydrogenated alprenolol derivative where the extra hydrogens are often tritiated. This radiolabeled form of ALPRENOLOL, a beta-adrenergic blocker, is used to label the beta-adrenergic receptor for isolation and study.Receptors, Adrenergic, beta: One of two major pharmacologically defined classes of adrenergic receptors. The beta adrenergic receptors play an important role in regulating CARDIAC MUSCLE contraction, SMOOTH MUSCLE relaxation, and GLYCOGENOLYSIS.Receptors, Adrenergic, alpha-1: A subclass of alpha-adrenergic receptors that mediate contraction of SMOOTH MUSCLE in a variety of tissues such as ARTERIOLES; VEINS; and the UTERUS. They are usually found on postsynaptic membranes and signal through GQ-G11 G-PROTEINS.Pindolol: A moderately lipophilic beta blocker (ADRENERGIC BETA-ANTAGONISTS). It is non-cardioselective and has intrinsic sympathomimetic actions, but little membrane-stabilizing activity. (From Martindale, The Extra Pharmocopoeia, 30th ed, p638)Propanolamines: AMINO ALCOHOLS containing the propanolamine (NH2CH2CHOHCH2) group and its derivatives.TritiumLigands: A molecule that binds to another molecule, used especially to refer to a small molecule that binds specifically to a larger molecule, e.g., an antigen binding to an antibody, a hormone or neurotransmitter binding to a receptor, or a substrate or allosteric effector binding to an enzyme. Ligands are also molecules that donate or accept a pair of electrons to form a coordinate covalent bond with the central metal atom of a coordination complex. (From Dorland, 27th ed)Receptors, Serotonin: Cell-surface proteins that bind SEROTONIN and trigger intracellular changes which influence the behavior of cells. Several types of serotonin receptors have been recognized which differ in their pharmacology, molecular biology, and mode of action.CHO Cells: CELL LINE derived from the ovary of the Chinese hamster, Cricetulus griseus (CRICETULUS). The species is a favorite for cytogenetic studies because of its small chromosome number. The cell line has provided model systems for the study of genetic alterations in cultured mammalian cells.Adrenergic alpha-Antagonists: Drugs that bind to but do not activate alpha-adrenergic receptors thereby blocking the actions of endogenous or exogenous adrenergic agonists. Adrenergic alpha-antagonists are used in the treatment of hypertension, vasospasm, peripheral vascular disease, shock, and pheochromocytoma.Iodine Radioisotopes: Unstable isotopes of iodine that decay or disintegrate emitting radiation. I atoms with atomic weights 117-139, except I 127, are radioactive iodine isotopes.Receptors, Purinergic P1: A class of cell surface receptors that prefer ADENOSINE to other endogenous PURINES. Purinergic P1 receptors are widespread in the body including the cardiovascular, respiratory, immune, and nervous systems. There are at least two pharmacologically distinguishable types (A1 and A2, or Ri and Ra).Cricetinae: A subfamily in the family MURIDAE, comprising the hamsters. Four of the more common genera are Cricetus, CRICETULUS; MESOCRICETUS; and PHODOPUS.Receptors, Angiotensin: Cell surface proteins that bind ANGIOTENSINS and trigger intracellular changes influencing the behavior of cells.Binding Sites: The parts of a macromolecule that directly participate in its specific combination with another molecule.Guinea Pigs: A common name used for the genus Cavia. The most common species is Cavia porcellus which is the domesticated guinea pig used for pets and biomedical research.Dose-Response Relationship, Drug: The relationship between the dose of an administered drug and the response of the organism to the drug.Protein Binding: The process in which substances, either endogenous or exogenous, bind to proteins, peptides, enzymes, protein precursors, or allied compounds. Specific protein-binding measures are often used as assays in diagnostic assessments.Kinetics: The rate dynamics in chemical or physical systems.Cell Membrane: The lipid- and protein-containing, selectively permeable membrane that surrounds the cytoplasm in prokaryotic and eukaryotic cells.Brain: The part of CENTRAL NERVOUS SYSTEM that is contained within the skull (CRANIUM). Arising from the NEURAL TUBE, the embryonic brain is comprised of three major parts including PROSENCEPHALON (the forebrain); MESENCEPHALON (the midbrain); and RHOMBENCEPHALON (the hindbrain). The developed brain consists of CEREBRUM; CEREBELLUM; and other structures in the BRAIN STEM.Cerebral Cortex: The thin layer of GRAY MATTER on the surface of the CEREBRAL HEMISPHERES that develops from the TELENCEPHALON and folds into gyri and sulchi. It reaches its highest development in humans and is responsible for intellectual faculties and higher mental functions.Allosteric Regulation: The modification of the reactivity of ENZYMES by the binding of effectors to sites (ALLOSTERIC SITES) on the enzymes other than the substrate BINDING SITES.Drug Discovery: The process of finding chemicals for potential therapeutic use.Allosteric Site: A site on an enzyme which upon binding of a modulator, causes the enzyme to undergo a conformational change that may alter its catalytic or binding properties.Gallamine Triethiodide: A synthetic nondepolarizing blocking drug. The actions of gallamine triethiodide are similar to those of TUBOCURARINE, but this agent blocks the cardiac vagus and may cause sinus tachycardia and, occasionally, hypertension and increased cardiac output. It should be used cautiously in patients at risk from increased heart rate but may be preferred for patients with bradycardia. (From AMA Drug Evaluations Annual, 1992, p198)Drug Design: The molecular designing of drugs for specific purposes (such as DNA-binding, enzyme inhibition, anti-cancer efficacy, etc.) based on knowledge of molecular properties such as activity of functional groups, molecular geometry, and electronic structure, and also on information cataloged on analogous molecules. Drug design is generally computer-assisted molecular modeling and does not include pharmacokinetics, dosage analysis, or drug administration analysis.Drug Evaluation, Preclinical: Preclinical testing of drugs in experimental animals or in vitro for their biological and toxic effects and potential clinical applications.Encyclopedias as Topic: Works containing information articles on subjects in every field of knowledge, usually arranged in alphabetical order, or a similar work limited to a special field or subject. (From The ALA Glossary of Library and Information Science, 1983)Molecular Sequence Data: Descriptions of specific amino acid, carbohydrate, or nucleotide sequences which have appeared in the published literature and/or are deposited in and maintained by databanks such as GENBANK, European Molecular Biology Laboratory (EMBL), National Biomedical Research Foundation (NBRF), or other sequence repositories.Glycosaminoglycans: Heteropolysaccharides which contain an N-acetylated hexosamine in a characteristic repeating disaccharide unit. The repeating structure of each disaccharide involves alternate 1,4- and 1,3-linkages consisting of either N-acetylglucosamine or N-acetylgalactosamine.Receptors, Chemokine: Cell surface glycoproteins that bind to chemokines and thus mediate the migration of pro-inflammatory molecules. The receptors are members of the seven-transmembrane G protein-coupled receptor family. Like the CHEMOKINES themselves, the receptors can be divided into at least three structural branches: CR, CCR, and CXCR, according to variations in a shared cysteine motif.Receptors, CXCR4: CXCR receptors with specificity for CXCL12 CHEMOKINE. The receptors may play a role in HEMATOPOIESIS regulation and can also function as coreceptors for the HUMAN IMMUNODEFICIENCY VIRUS.Chemokine CXCL12: A CXC chemokine that is chemotactic for T-LYMPHOCYTES and MONOCYTES. It has specificity for CXCR4 RECEPTORS. Two isoforms of CXCL12 are produced by alternative mRNA splicing.Chemokine CXCL10: A CXC chemokine that is induced by GAMMA-INTERFERON and is chemotactic for MONOCYTES and T-LYMPHOCYTES. It has specificity for the CXCR3 RECEPTOR.Chemokine CCL5: A CC-type chemokine that is a chemoattractant for EOSINOPHILS; MONOCYTES; and LYMPHOCYTES. It is a potent and selective eosinophil chemotaxin that is stored in and released from PLATELETS and activated T-LYMPHOCYTES. Chemokine CCL5 is specific for CCR1 RECEPTORS; CCR3 RECEPTORS; and CCR5 RECEPTORS. The acronym RANTES refers to Regulated on Activation, Normal T Expressed and Secreted.Fluorine Radioisotopes: Unstable isotopes of fluorine that decay or disintegrate emitting radiation. F atoms with atomic weights 17, 18, and 20-22 are radioactive fluorine isotopes.Positron-Emission Tomography: An imaging technique using compounds labelled with short-lived positron-emitting radionuclides (such as carbon-11, nitrogen-13, oxygen-15 and fluorine-18) to measure cell metabolism. It has been useful in study of soft tissues such as CANCER; CARDIOVASCULAR SYSTEM; and brain. SINGLE-PHOTON EMISSION-COMPUTED TOMOGRAPHY is closely related to positron emission tomography, but uses isotopes with longer half-lives and resolution is lower.gamma-Synuclein: A homolog of ALPHA-SYNUCLEIN that plays a role in neurofilament network integrity. It is overexpressed in a variety of human NEOPLASMS and may be involved in modulating AXON architecture during EMBRYONIC DEVELOPMENT and in the adult. Gamma-Synuclein may also activate SIGNAL TRANSDUCTION PATHWAYS associated with ETS-DOMAIN PROTEIN ELK-1.Synucleins: A family of homologous proteins of low MOLECULAR WEIGHT that are predominately expressed in the BRAIN and that have been implicated in a variety of human diseases. They were originally isolated from CHOLINERGIC FIBERS of TORPEDO.Radiochemistry: The study of the chemical and physical phenomena of radioactive substances.Tissue Distribution: Accumulation of a drug or chemical substance in various organs (including those not relevant to its pharmacologic or therapeutic action). This distribution depends on the blood flow or perfusion rate of the organ, the ability of the drug to penetrate organ membranes, tissue specificity, protein binding. The distribution is usually expressed as tissue to plasma ratios.Radiopharmaceuticals: Compounds that are used in medicine as sources of radiation for radiotherapy and for diagnostic purposes. They have numerous uses in research and industry. (Martindale, The Extra Pharmacopoeia, 30th ed, p1161)Receptors, Serotonin, 5-HT4: A subtype of G-protein-coupled SEROTONIN receptors that preferentially couple to GS STIMULATORY G-PROTEINS resulting in increased intracellular CYCLIC AMP. Several isoforms of the receptor exist due to ALTERNATIVE SPLICING of its mRNA.GTP-Binding Proteins: Regulatory proteins that act as molecular switches. They control a wide range of biological processes including: receptor signaling, intracellular signal transduction pathways, and protein synthesis. Their activity is regulated by factors that control their ability to bind to and hydrolyze GTP to GDP. EC 3.6.1.-.Receptors, G-Protein-Coupled: The largest family of cell surface receptors involved in SIGNAL TRANSDUCTION. They share a common structure and signal through HETEROTRIMERIC G-PROTEINS.GTP-Binding Protein alpha Subunits, Gi-Go: A family of heterotrimeric GTP-binding protein alpha subunits that were originally identified by their ability to inhibit ADENYLYL CYCLASES. Members of this family can couple to beta and gamma G-protein subunits that activate POTASSIUM CHANNELS. The Gi-Go part of the name is also spelled Gi/Go.Mice, Transgenic: Laboratory mice that have been produced from a genetically manipulated EGG or EMBRYO, MAMMALIAN.Apocynaceae: The dogbane family of the order Gentianales. Members of the family have milky, often poisonous juice, smooth-margined leaves, and flowers in clusters. Asclepiadacea (formerly the milkweed family) has been included since 1999 and before 1810.Diffusion: The tendency of a gas or solute to pass from a point of higher pressure or concentration to a point of lower pressure or concentration and to distribute itself throughout the available space. Diffusion, especially FACILITATED DIFFUSION, is a major mechanism of BIOLOGICAL TRANSPORT.Membrane Microdomains: Detergent-insoluble CELL MEMBRANE components. They are enriched in SPHINGOLIPIDS and CHOLESTEROL and clustered with glycosyl-phosphatidylinositol (GPI)-anchored proteins.Adenylate Cyclase: An enzyme of the lyase class that catalyzes the formation of CYCLIC AMP and pyrophosphate from ATP. EC 4.6.1.1.Dimerization: The process by which two molecules of the same chemical composition form a condensation product or polymer.Fluorescence Resonance Energy Transfer: A type of FLUORESCENCE SPECTROSCOPY using two FLUORESCENT DYES with overlapping emission and absorption spectra, which is used to indicate proximity of labeled molecules. This technique is useful for studying interactions of molecules and PROTEIN FOLDING.
Testing for Illegal Drugs Radioligand binding assay When multiple assays measure the same target their results and utility may ... DNase footprinting assay Filter binding assay Gel shift assay Bicinchoninic acid assay (BCA assay) Bradford protein assay Lowry ... Chemotaxis assay Secretion assays Apoptosis assays such as the DNA laddering assay, the Nicoletti assay, caspase activity ... MTT assay Cell Counting Kit-8 (WST-8 based cell viability assay) SRB (Sulforhodamine B) assay CellTiter-Glo® Luminescent Cell ...
"Calculations and Instrumentation used for Radioligand Binding Assays". Assay Guidance Manual: 1-21. Davenport, Anthony P. (2005 ... binding-assay.com/binding-assay-types/solid-phase-assays/on-bead-assays Moss, ed. by Tom (2001). "Filter-Binding Assays". DNA- ... Ligand binding assays (LBA) is an assay, or an analytic procedure, whose procedure or method relies on the binding of ligand ... There are numerous types of ligand binding assays, both radioactive and non-radioactive. As such, ligand binding assays are a ...
One of the methods researchers used to guide these alterations was radioligand binding thermostability assay. The assay is ... Thermofluor variant specific for flavin-binding proteins. Analogous to thermofluor binding assays, a small volume of protein ... The radioligand concentration is high enough to saturate the protein. Denatured protein is unable to bind the radioligand and ... Biochemical assays require a catalytic activity of the protein in question as well as a specific assay. Circular dichroism and ...
"Calculations and Instrumentation used for Radioligand Binding Assays". Assay Guidance Manual: 1-21. ... 7,0 7,1 7,2 7,3 7,4 7,5 Anthony P. Davenport; Fraser D. Russel (1996). "Radioligand Binding Assays: Theory and Practice". In ... 5,0 5,1 5,2 5,3 5,4 5,5 De Jong, L. A. A.; Uges, D. R. A.; Franke, J. P.; Bischoff, R. (2005). "Receptor-ligand binding assays ... 2009). Ligand-binding assays development, validation, and implementation in the drug development arena. Hoboken, N.J.: John ...
... of an antagonist can be determined experimentally using Schild regression or for competitive antagonists in radioligand binding ... In functional antagonist assays, a dose-response curve measures the effect of the ability of a range of concentrations of ... Altering the amount of antagonist used in the assay can alter the dose ratio. In Schild regression, a plot is made of the log ( ... Binding occurs as a result of non-covalent interactions between the receptor and its ligand, at locations called the binding ...
"Development of homogeneous high-affinity agonist binding assays for 5-HT2 receptor subtypes". ASSAY and Drug Development ... "Pharmacological characterisation of the agonist radioligand binding site of 5-HT(2A), 5-HT(2B) and 5-HT(2C) receptors". Naunyn- ...
ISBN 978-3-639-31160-0. [page needed] Wienken CJ, Baaske P, Rothbauer U, Braun D, Duhr S (2010). "Protein-binding assays in ... Rotating cell‑based ligand binding assay using radioactivity or fluorescence, is a recent method that measures molecular ... Björke, Henrik; Andersson, Karl (2006-01-01). "Measuring the affinity of a radioligand with its receptor using a rotating cell ... The increase in the polarization of the fluorescence upon binding of the labeled protein to its binding partner can be used to ...
Ligand binding assays (LBA) is an assay, or an analytic procedure, whose procedure or method relies on the binding of ligand molecules to receptors, antibodies or other macromolecules. A detection method is used to determine the presence and extent of the ligand-receptor complexes formed, and this is usually determined electrochemically or through a fluorescence detection method. This type of analytic test can be used to test for the presence of target molecules in a sample that are known to bind to the receptor. There are numerous types of ligand binding assays, both radioactive and non-radioactive. As such, ligand binding assays are a superset of radiobinding assays, which are the conceptual inverse of radioimmunoassays (RIA). Some newer ...
Knight AR, Misra A, Quirk K, Benwell K, Revell D, Kennett G, Bickerdike M. Pharmacological characterisation of the agonist radioligand binding site of 5-HT(2A), 5-HT(2B) and 5-HT(2C) receptors. Naunyn Schmiedebergs Archives of Pharmacology. 2004;370:114-123. DOI:10.1007/s00210-004-0951-4 PMID 15322733 ...
A receptor antagonist is a type of receptor ligand or drug that blocks or dampens a biological response by binding to and blocking a receptor rather than activating it like an agonist. They are sometimes called blockers; examples include alpha blockers, beta blockers, and calcium channel blockers. In pharmacology, antagonists have affinity but no efficacy for their cognate receptors, and binding will disrupt the interaction and inhibit the function of an agonist or inverse agonist at receptors. Antagonists mediate their effects by binding to the active site or to the allosteric site on a receptor, or they may interact at unique binding sites not normally involved in the biological regulation of the receptor's activity. Antagonist activity may be reversible or irreversible depending on the longevity of the antagonist-receptor complex, which, in turn, depends on the nature of antagonist-receptor binding. The majority of drug ...
Lo filosòf grèc Aristòtel reconeis jà als vèrms de tèrra una activitat biologica essenciala, los nomenava los « intestins de la tèrra ». Charles Darwin es fòrça interessat al sòl coma supòrt de vida e produch de la vida. Foguèt un dels primièrs a reabilitar lo vèrm de tèrra, alara considerat coma noisible a l'agricultura. Darwin aviá observat que los rèstes arqueologics essent sovent protegits per lor aclapament pro rapid sota la tèrra producha a partir de la vegetacion mòrta e pes organismes del sòl. Contribuiguèt a far conéisser l'importança dels organismes escavaires coma lo vèrm de tèrra pels sòls[40]. Dins un obratge publicat lo 10 d'octobre de 1881 e titulat « The formation of vegetable mould through the action of worms with observations on their habits », « L'Origina des espècias »), tractèt de l'importança del trabalh de bioturbacion dels vèrms de tèrra sus la genèsi, l'erosion e la fertilitat del sòl. Un critica ne fa lo comentari seguent: « Al ...
Half maximal effective concentration (EC50) refers to the concentration of a drug, antibody or toxicant which induces a response halfway between the baseline and maximum after a specified exposure time.[1] It is commonly used as a measure of a drug's potency. EC50 is expressed in molar units (M), where 1 M is equivalent to 1 mol/L. The EC50 of a graded dose response curve therefore represents the concentration of a compound where 50% of its maximal effect is observed.[2] The EC50 of a quantal dose response curve represents the concentration of a compound where 50% of the population exhibit a response,[3] after a specified exposure duration. It is also related to IC50 which is a measure of a compound's inhibition (50% inhibition). For competition binding assays and functional antagonist assays IC50 is the most common summary measure of the dose-response curve. For agonist/stimulator assays ...
如左圖所示,兩根曲線所代表的分別是兩種與受體結合親和性不同的配體。配體對受體的結合能力通常是由半數的受體結合位點被配體佔據時的濃度表徵的,該濃度稱爲IC50(英语:IC50),與解離常數Kd有關但有區別。圖中紅色曲線所表示的配體比起綠色曲線所表示的配體有更高的結合親和性和更小的Kd值。如果這兩種配體同時存在的話,那麼高親和性的配體與受體結合更多。這也就是一氧化碳能優先於氧氣與血紅蛋白結合,從而導致一氧化碳中毒的原理。. 配體對受體的結合親和性通常藉由用放射性同位素標記的配體来確定,這種配體稱爲「熱配體」。「同源競爭性結合實驗」(Homologous competitive binding experiments)的原理就是讓帶有放射性的「熱配體」和不帶放射性的「冷配體」競爭結合位點[4]。不過,表面等離子體共振和雙偏振干涉(英语:dual polarisation ...
如左圖所示,兩根曲線所代表的分別是兩種與受體結合親和性不同的配體。配體對受體的結合能力通常是由半數的受體結合位點被配體佔據時的濃度表徵的,該濃度稱爲IC50(英语:IC50),與解離常數Kd有關但有區別。圖中紅色曲線所表示的配體比起綠色曲線所表示的配體有更高的結合親和性和更小的Kd值。如果這兩種配體同時存在的話,那麼高親和性的配體與受體結合更多。這也就是一氧化碳能優先於氧氣與血紅蛋白結合,從而導致一氧化碳中毒的原理。. 配體對受體的結合親和性通常藉由用放射性同位素標記的配體来確定,這種配體稱爲「熱配體」。「同源競爭性結合實驗」(Homologous competitive binding experiments)的原理就是讓帶有放射性的「熱配體」和不帶放射性的「冷配體」競爭結合位點[4]。不過,表面等離子體共振和雙偏振干涉(英语:dual polarisation ...
Ligand binding assays (LBA) is an assay, or an analytic procedure, whose procedure or method relies on the binding of ligand molecules to receptors, antibodies or other macromolecules. A detection method is used to determine the presence and extent of the ligand-receptor complexes formed, and this is usually determined electrochemically or through a fluorescence detection method. This type of analytic test can be used to test for the presence of target molecules in a sample that are known to bind to the receptor. There are numerous types of ligand binding assays, both radioactive and non-radioactive. As such, ligand binding assays are a superset of radiobinding assays, which are the conceptual inverse of radioimmunoassays (RIA). Some newer ...
... (EPH) is a psychostimulant and a close analog of methylphenidate. Ethylphenidate acts as both a dopamine reuptake inhibitor and norepinephrine reuptake inhibitor, meaning it effectively boosts the levels of the norepinephrine and dopamine neurotransmitters in the brain, by binding to, and partially blocking the transporter proteins that normally remove those monoamines from the synaptic cleft. However, considering the close similarities between ethylphenidate and methylphenidate and the fact that methylphenidate, like cocaine, actually does not primarily act as a "classical" reuptake inhibitor, but rather as an "inverse agonist at the DAT" (also called a "negative allosteric modulator at the DAT"), it is at least very likely that ethylphenidate also primarily acts as an inverse DAT agonist instead of (or at least only secondarily) as a classical reuptake inhibitor (which could be called a "competitive antagonist at the DAT" using a similar terminology as "negative allosteric ...
Trimetaphan is a sulfonium compound and therefore carries a positive charge. Being charged, it cannot cross lipid cell membranes, such as those that comprise the blood-brain barrier. Due to this, trimethaphan does not have any effect on the central nervous system. The ciliary muscle of the eye functions to round the lens for accommodation and is controlled mainly by parasympathetic system input. With administration of a ganglion-blocking drug, the ciliary muscle cannot contract (cycloplegia) and the patient loses the ability to focus their eyes. Trimetaphan has a strong effect on the cardiovascular system. The size of blood vessels is primarily controlled by the sympathetic nervous system. Loss of sympathetic system input to the blood vessels causes them to get larger (vasodilation) which has the effect of lowering blood pressure. Postural hypotension is a common side effect of such drugs. Trimethaphan causes a histamine release which further lowers blood pressure. Effects on the heart include a ...
In competitive inhibition, an inhibitor that resembles the normal substrate binds to the enzyme, usually at the active site, and prevents the substrate from binding.[8] At any given moment, the enzyme may be bound to the inhibitor, the substrate, or neither, but it cannot bind both at the same time. During competitive inhibition, the inhibitor and substrate compete for the active site. The active site is a region on an enzyme which a particular protein or substrate can bind to. The active site will only allow one of the two complexes to bind to the site therefore either allowing for a reaction to occur or yielding it. In competitive inhibition the inhibitor resembles the substrate therefore taking its place and binding to the active site of an enzyme. Increasing the substrate concentration would diminish the "competition" for the substrate to properly bind to the active site and allow a reaction to occur.[3] When the substrate is of higher concentration than that of the ...
Half maximal effective concentration (EC50) refers to the concentration of a drug, antibody or toxicant which induces a response halfway between the baseline and maximum after a specified exposure time.[1] It is commonly used as a measure of a drug's potency. EC50 is expressed in molar units (M), where 1 M is equivalent to 1 mol/L. The EC50 of a graded dose response curve therefore represents the concentration of a compound where 50% of its maximal effect is observed.[2] The EC50 of a quantal dose response curve represents the concentration of a compound where 50% of the population exhibit a response,[3] after a specified exposure duration. It is also related to IC50 which is a measure of a compound's inhibition (50% inhibition). For competition binding assays and functional antagonist assays IC50 is the most common summary measure of the dose-response curve. For agonist/stimulator assays ...
... (also βARKct) is a peptide composed of the last 194 amino acid residues of the carboxyl-terminus of beta adrenergic receptor kinase 1 (βARK1). It binds the βγ subunits of G proteins located in the plasma membrane of cells. It is currently an experimental gene therapy for the treatment of heart failure. During heart failure, the heart is not able to pump enough blood to the rest of the body and will begin to undergo processes in order to compensate for its decreased function. These processes will attempt to increase the heart's output; however, the heart may become overstressed and eventually dysfunctional as a result. The sympathetic nervous system increases norepinephrine release to stimulate β-adrenergic receptors (βARs) located on heart cell (cardiomyocyte) membranes to increase the heart's rate and force of contraction. If the heart is already stressed or damaged, this will cause the heart to work above its capacity. Continuous ...
What is Radioligand assay? Meaning of Radioligand assay as a legal term. What does Radioligand assay mean in law? ... Definition of Radioligand assay in the Legal Dictionary - by Free online English dictionary and encyclopedia. ... The ER radioligand assays measure displacement of [[.sup.3]H]-estradiol at final ligand concentrations of 0.1 nM (hER) and 0.7 ... GAD 65-ligand binding assay ... Radioligand assay legal definition of Radioligand assay https ...
Binding Assay Neurotransmitter Receptor Synaptic Membrane Ligand Binding Assay Radioreceptor Assay These keywords were added by ... Enna S.J. (1984) Radioligand Binding Assays. In: Cattabeni F., Nicosia S. (eds) Principles and Methods in Receptor Binding. ... One of the more powerful methods for this purpose has been the radioligand binding assay (Yamamura et al, 1978). With this ... Because of its simplicity and power, the radioligand binding assay has become one of the more popular tools in neurobiological ...
... binding assays to determine agonist affinity and estimate receptor binding sites on these cells in competitive binding assays ... Radioligand binding Assay Using cell-line transfected with a neuropeptide GPCR, Ive carried out [125-I] radioligand ... Home/ Forums/ Pharmacology and Drug Discovery: Assay Development & Protocols/ Radioligand binding Assay. ... I then looked at the effect of a drug which competitively inhibited radioligand binding to the receptor. Using a fixed [drug ...
Were developing some saturation binding curves for a muscarinic cholinergic receptor binding assay. The specific binding curve ... The non specific binding is low (under 20% of total) and is linear across all the radioligand co... ... but then it all of a sudden takes off at higher radioligand concentrations and keeps increasing. ... Saturation curve for radioligand binding assay - posted in Biochemistry: Hi! ...
Radioligand-Binding Assays.. Binding experiments were performed on 20-μg membrane extracts with 1-2 nM [3H]raclopride or 1 nM [ ... GTPγS Assay.. Agonist-mediated [35S]GTPγS incorporation into specific G proteins was assessed as described (21). GDP (final ... e) Competition binding of [3H]raclopride by SKF83822 indicated high-affinity binding of the agonist to D2 receptors in D1-D2HEK ... a) Comparison of binding on membranes from D2HEK cells and D1-D2HEK cells reveals a high-affinity binding site for SKF83959 ...
Radioligand binding assays. (−)-[3H]-nicotine competition binding assays: rat brain membranes. P2 membranes (250 μg protein) ... Because the α4β2 subtype is a candidate for this role, we examined the behavior of (±)-UB-165 in a neurochemical assay for this ... for its ability to displace the binding of a number of nicotinic radioligands (Fig.2, Table1). Radioligand binding assays, at ... Competition binding assays for [3H]-nicotine binding sites (A) and [125I]-αBgt binding sites (B) in rat brain membranes, [3H]- ...
We offer a range of tools for receptor-ligand binding assays including radioligands, receptor-transfected cell membranes, and ... A receptor ligand binding assay allows for the study and simple imaging of cell surface receptors for research and diagnostic ... We offer a range of tools for receptor ligand binding assays including radioligands, receptor-transfected cell membranes, and ... Our collection of receptor ligand binding related assays includes fluorescence, LANCE? and DELFIA? time-resolved fluorescence, ...
Radioligand binding assays. Membranes from HEK-293 cells stably expressing the mouse A1AR, A2AAR, or A3AR were used for ... Membranes were filtered on Millipore MultiScreen assay system 96-well filtration plates and washed three times with ice-cold ... Competition binding assays were used to determine the binding affinities of various adenosine analogs at the murine A1AR, A2AAR ... We gratefully acknowledge Melissa Marshall for technical assistance with radioligand binding assays and Rosa Chen for mouse ...
... of four individual assays. (b) Affinity of 3943 to 5HT2CR determined by radioligand binding assay. (c) Inhibition of 5HT2CR ... Radioligand binding assays for different receptors. The 5-HT2A/2B/2CR binding assays were provided by the National Institute of ... Subsequent radioligand binding assay revealed that four ligands (901, 3286, 4170, and 4279) augmented peptide binding to the ... 10 nM binding affinity to the receptor as determined by the radioligand competition assay. Results from a thermal shift assay ...
Radioligand binding competition assay. HEK 293E cells were seeded in Dulbeccos modified Eagles medium supplemented with 10% ... Radioligand binding assays were performed 48 hours after transfection. Cells were washed twice in phosphate-buffered saline ( ... F) Binding of WT CXCL12 was measured by radioligand displacement of 125I-CXCL12 from CXCR4WT or CXCR4 (I4E/I6E) in membranes ... A) Binding of the indicated CXCL12 proteins was measured by radioligand displacement of 125I-CXCL12 from CXCR4-containing ...
Radioligand Binding Assays.. Competition binding assays against the CB1 receptor antagonist [3H]SR141716A rimonabant were ... 35S]GTPγS Binding Assays.. Assays were performed in triplicate in assay buffer containing 20 mM HEPES, 3 mM MgCl2, 60 mM NaCl, ... the free radioligand concentration was determined by subtraction of total bound radioligand from the added radioligand ... Data for specific radioligand binding and free radioligand concentration were fitted to equations describing one- or two- ...
Radioligand Binding Assays.. Membrane preparations of FlpInCHO-huGLP-1R were prepared as described previously (Avlani et al., ... cAMP Accumulation Assay.. FlpInCHO-huGLP-1R cells were seeded at a density of 5 × 104 cells/well into 96-well culture plates ... In binding assays, hydroxyl flavonols and catechin both displayed weak inhibition of the radioligand but displayed neutral ... In this case, basal defines the specific binding of the radioligand that is equivalent to nonspecific ligand binding, whereas E ...
Moreover, the same rank order of binding affinities was also observed in a radioligand-binding assay (Fig. 1D and Table 1). ... and radioligand-binding assays.. 125I-MCP-1 competition binding was measured in membrane preparations of c-Myc-FLAG-CCR2 Flp-In ... Competitive binding assays were performed as described by Zweemer et al. (48). Briefly, binding assays were performed in a 100- ... Membrane preparation and radioligand-binding assays. Cell membranes were prepared by detaching the cells from the flasks, ...
"Calculations and Instrumentation used for Radioligand Binding Assays". Assay Guidance Manual: 1-21. Davenport, Anthony P. (2005 ... binding-assay.com/binding-assay-types/solid-phase-assays/on-bead-assays Moss, ed. by Tom (2001). "Filter-Binding Assays". DNA- ... Ligand binding assays (LBA) is an assay, or an analytic procedure, whose procedure or method relies on the binding of ligand ... There are numerous types of ligand binding assays, both radioactive and non-radioactive. As such, ligand binding assays are a ...
Bare-filter migration (chemotaxis) assays. A total of 30 μl chemokine in RPMI 1640 (Sigma-Aldrich) containing 0.1% BSA (assay ... Radioligand binding. Radioligand-binding experiments were performed, as described previously (3). For saturation-binding ... In this study, we have used GAG binding-deficient chemokine mutants and cell-based functional (migration) assays to demonstrate ... To test whether CXCL12 and CXCL13 compete with CCL19 for binding to GAGs on the cell surface, we monitored the binding of [125I ...
Modified existing procedures for radioligand binding and enzyme assays to accommodate additional experimental parameters. ... Implemented centrifugal gel filtration assay for measuring ligand binding to soluble channels and ELISA for titering antibody ... radioligand binding; enzyme assays; FPLC; immunoprecipitation; sucrose density gradient centrifugation; ELISA Molecular Biology ... The observed GTP binding rate is limited by slow association of m1 receptor with Gq, but once associated GTP binds very rapidly ...
... radioligand for in vivo imaging of α-synuclein aggregation in the central nervous system (CNS). ... a Thioflavin T fluorescence assay; b 125I competitive binding assay; c 95% confidence intervals for Ki values are shown in ... An aliquot was assayed by analytical HPLC (Grace Altima C18 column, 250 × 4.6 mm), UV at 276 nm, mobile phase of acetonitrile/ ... a Thioflavin T fluorescence assay; b 125I competitive binding assay; c 95% confidence intervals for Ki values are shown in ...
Radioligand Binding Assay. For radioligand binding assays using filtration with a Brandel cell harvester (model M-30; Brandel, ... 2), radioligand binding assays were performed using [3H]kainate and [3H]MG (Fig. 3). Mutations of conserved residues in the ... From the supernatants, membranes were pelleted at 40,000×g for 20 min at 4 °C. For radioligand binding assay, membranes were ... before the radioligand binding assay was carried out. The presence of KAR subunits in membrane samples was confirmed using ...
Radioligand Binding Assays.. Saturation binding isotherms were established after the addition of 1 μg (hM3-R) or 10 μg (hM3- ... The filters were washed twice with assay buffer, and bound ligand was estimated by liquid scintillation counting. ... ERK1/2 Phosphorylation Assays.. ERK1/2 phosphorylation assays were performed using the AlphaScreen Surefire kit (PerkinElmer ... 2005) Probing the beta2 adrenoceptor binding site with catechol reveals differences in binding and activation by agonists and ...
Bound radioactivity was determined by liquid scintillation counting as described under Radioligand Binding Assays. ... which display partial agonist activity in certain assays. However, in this assay, clonidine caused the same degree of cAMP ... Radioligand Binding Assays.. Membranes were prepared from retinoic acid-differentiated SH-SY5Y cells. Cells were rinsed with ... Membranes were prepared from retinoic acid-differentiated SH-SY5Y cells as described under Radioligand Binding Assays. In some ...
The following total radioligand binding and non-specific binding (nsb) values are typically obtained with these assay systems: ... until assayed for hormone content. Growth hormone in media was measured by a standard double antibody RIA using components ... Specific binding is. defined as the total radioligand bound minus that bound in the presence of 1.0 μM SRIF. ... or in vitro as a radioligand in a somatostatin receptor binding assay. The peptide of the invention can also be used as vectors ...
Radioligand Binding Assays. The allosteric antagonist MPEP analog [3H]methoxyPEPy (Cosford et al., 2003) was used to evaluate ... in assay medium at a density of 20,000 cells/well for 24 hours before the assay. Assays were performed at the Vanderbilt ... Plasma Protein Binding and Nonspecific Binding in Brain Homogenate. The extent of plasma protein binding and nonspecific ... a panel of ancillary pharmacology binding assays measuring the percentage of displacement of an orthosteric radioligand at 66 ...
Short hairpin RNA design, generation, and transfection and radioligand-binding assay.. Stealth short hairpin (sh)RNA ... Briefly, we used 20 size-matched islets (for the ex vivo assays) and 4,000 cells/well INS-1E (for the in vitro assays). Islets ... Based on radioligand binding and real-time RT-PCR analysis, the expression of both β2AR protein and mRNA was significantly ... This complex binds to and cleaves mRNAs that match the small interfering RNA that is bound to it. We transfected INS-1E β-cells ...
Receptor Radioligand Binding Assay. Cardiac myocytes were homogenized and crude membranes were prepared by centrifuging at 35 ... Biochemical assays revealed that a progressive and persistent CaMKII activation was associated with a rapid desensitization of ... Radioligand binding assay of receptor density in crude membrane fraction revealed a trend of decrease (though statistically ... β1AR radioligand binding studies were performed in membranes (25 to 100 μg/tube) using the nonselective βAR antagonist ligand ...
Radioligand Competition Binding Assays. [125I]IBNtxA binding was carried out in membranes prepared from Chinese Hamster Ovary ( ... 35S]GTPγS Functional Assay. [35S]GTPγS binding was performed on membranes prepared from transfected cells stably expressing ... Initial investigations used in vitro radioligand binding assays with cell lines stably expressing murine opioid receptors ( ... Binding in MOR-1/CHO was carried out in 50 mM potassium phosphate buffer with 5 mM MgSO4 and 20 μg/mL protein, while binding in ...
  • 2377, it is made the duty of the secretary of the treasury to cause assays to be made at the mint of the United States, of certain coins made current by the said acts, and to make report of the result thereof to congress. (thefreedictionary.com)
  • In vitro assays in cultured INS-1E β-cells were carried out in order to clarify the mechanism by which β 2 AR deficiency affects glucose metabolism. (diabetesjournals.org)
  • Using Chinese hamster ovary cells expressing the human GLP-1R, we have now extended this work to identify the structural requirements of flavonoids to modify GLP-1R binding and signaling (cAMP formation and intracellular Ca 2+ mobilization) of each of the GLP-1R endogenous agonists, as well as the clinically used exogenous peptide mimetic exendin-4. (aspetjournals.org)
  • Here we used molecular modelling to produce a range of ligand binding domain (LBD) point mutants of GluK1-3 KAR subunits with and without altered agonist efficacy to further investigate the role of glutamate binding in surface trafficking and activation of homomeric and heteromeric KARs using endoglycosidase digestion, cell surface biotinylation and imaging of changes in intracellular Ca 2+ concentration [Ca 2+ ] i . (springer.com)
  • In addition, IA-2 (intracellular domain), GAD65, and zinc transporter 8 autoantibodies were assayed. (diabetesjournals.org)
  • But back to what Robert was asking earlier, I think ideally you probably want to have a combination of an in vitro cell-based assay and a biochemical assay just to confirm that whatever you identify in a cell-based assay is really acting via the receptor and not some secondary response in an intracellular location. (ddw-online.com)
  • It is perhaps surprising that the pattern of regulation was very similar for the wild-type and RASSL forms, whether exploring initial conformational changes that occur upon ligand binding, interactions with β-arrestin 2, receptor internalization, ligand-induced phosphorylation of the ERK1/2 MAP kinases, or the extent and profile of phosphorylation of the receptor in response to appropriate agonists. (aspetjournals.org)
  • In vitro, 3 and its analogs were potent agonists in [ 35 S]GTP γ S assays at the mu opioid receptor but failed to recruit β -arrestin-2, which is associated with opioid side effects. (pubmedcentralcanada.ca)
  • Strategically located in the San Francisco Bay biotechnology region, SRI's high-throughput Screening Core Facility specializes in in vitro assay development and automation for high-throughput screening (HTS), HTS campaigns, and lead optimization for drug discovery. (sri.com)
  • The facility performs both HTS (384-well) and mid-throughput screening (MTS) (96-well) assays. (sri.com)
  • 36. A method for screening of chemical libraries, for catalysis, for facilitating synthesis, for analyte determination using ligand binding assays and/or agglutination assays, for therapeutic purposes, or for controlled release comprising using the molecularly imprinted microspheres according to claim 1. (freepatentsonline.com)
  • With a flexibility to adapt assays developed at the client's site, we take up the task of screening at our facility. (gvkbio.com)
  • The dedicated facility for radioactive assay readouts enables us to handle assay volumes that range from low to high throughput screening of drug candidates using radiolabeled C, P, H and I reagents. (gvkbio.com)
  • In the past decades, the rapid progress in developing functional assays and instrumentation has enabled high throughput screening (HTS) campaigns on an expanding list of channel types. (nature.com)
  • WuXi AppTec's discovery biology services, which are part of our integrated pharmaceutical services, include reagent generation, assay development, screening, biomarker research, custom monoclonal antibody generation, and stable line development, as well as biosafety and adventitious virus testing. (wuxiapptec.com)
  • We used the R-CEPIAer endoplasmic reticulum calcium reporter to functionally assay for Gq-coupled receptor signaling, and investigated the bis-quinolinium cyclophanes as antagonists of M3 mACHR activation in transfected CHO cells. (frontiersin.org)
  • Through the development of RIA technology, researchers have been able to move beyond the use of radioactivity, and instead, use liquid- and solid-phase, competitive, and immunoradiometric assays. (wikipedia.org)
  • Levels of radioactivity for a radioligand (per mole) are referred to as the specific activity (SA), which is measured in Ci/mmol. (wikipedia.org)
  • The initial studies suggested that further structural optimization of [ 11 C] 2a and [ 18 F] 2b is necessary in order to identify a highly specific positron emission tomography (PET) radioligand for in vivo imaging of α-synuclein aggregation in the central nervous system (CNS). (mdpi.com)
  • Yes, there's always the issue of whether an in vitro cell-based assay will truly mimic the in vivo response. (ddw-online.com)
  • Guanosine 5'-(beta, gamma-imido)triphosphate greatly reduced the amount of [125I]PIC bound (greater than 80%), without changing the Kd of the residual binding. (biomedsearch.com)
  • Receptor ligand binding is used in drug development applications to identify blocking antibodies or inhibitors that can modulate downstream signaling events, and is often used to screen for drugs that target hormone and neurotransmitter activity. (iktsm.tw)
  • Additionally, 3 developed analgesic tolerance more slowly than morphine, showed limited physical dependence, respiratory depression, constipation, and displayed no reward or aversion in CPP/CPA assays, suggesting that analogs might represent a promising new generation of novel pain relievers. (pubmedcentralcanada.ca)
  • The results from the assay validation indicative of its overall robustness in terms of sensitivity, specificity, reproducibility, and stability are presented here. (enets.org)
  • Analysis of the inhibition data by proteochemometric modeling suggested the possibility for different binding poses of the shortened peptides compared to the octapeptides, which was supported by results of docking of WYCW-NH2 into the X-ray structure of DEN-3 protease. (diva-portal.org)
  • GVK BIO offers customized assay development solutions to help you reach your goals quickly and cost effectively. (gvkbio.com)
  • Here, we report the development of an anti-FRα antibody-drug conjugate (ADC), consisting of a FRα-binding antibody attached to a highly potent maytansinoid that induces cell-cycle arrest and cell death by targeting microtubules. (aacrjournals.org)
  • miRNAs are small non-coding RNAs that post-transcriptionally regulate gene expression by binding to complementary sequences on target mRNAs and their expression is often dysregulated in cancer. (enets.org)
  • GTP-bound Gα subunit then detaches from the Gαβγ complex and the dissociated βγ and Gα-GTP subunits are capable of downstream signaling. (gvkbio.com)