Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0027960 (mole)
 21,279 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

In a previous publication, we have described in detail how we used small angle x-ray diffraction to determine the topography of (-)-delta 8-tetrahydrocannabinol (delta 8-THC) in dimyristoylphosphatidylcholine (DMPC) bilayers, and to deduce the conformation of the THC side chain by using the iodo-analog (5'-I-delta 8-THC) in the model membrane. We have now extended our studies to synaptic plasma membrane systems where the cannabinoids are believed to exert part of their pharmacological effects. Synaptic plasma membranes (SPM) were isolated from fresh bovine brains and delta 8-THC was incorporated into the membranes. By comparing the electron density profiles of drug free and drug-containing SPM preparations, we observed an electron density increase due to the presence of delta 8-THC in a region centered at 9.2 A from the terminal methyl groups of the membrane bilayer. In an attempt to dissect the effects of different membrane components on the topography of delta 8-THC, we carried out parallel experiments using membrane preparations from the synaptosomal membrane total lipid extract (TLX) as well as from bovine brain phosphatidyl choline extract (PCX) containing 30 mole percent cholesterol (Chol). Our results regarding the topography of delta 8-THC and 5'-I-delta 8-THC in these lipid membranes show that the TLX bilayer simulates the natural membrane environment very closely whereas in the PCX/Chol bilayer delta 8-THC resides at a location approximately 4 A closer to the membrane interface, similar to that found in our previous study using DMPC model membrane.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Small angle x-ray diffraction studies on the topography of cannabinoids in synaptic plasma membranes. 166 18

The useful TDxFLx calibration data was obtained for the interpretation of the interactions of the abused drugs to sheep antiserum protein. The antibody of TDxFLx calibrators was prepared from sheep antiserum. Furthermore these data can be used to interpret the abused drug-protein binding phenomena in human body and the TDxFLx screening results of the abused drugs in urine samples. TDxFLx system uses fluorescence polarization immunoassay technique that is a competitive binding immunoassay methodology to allow tracer-labeled antigen (*Drug) and patient antigen (Drug) to compete for the same binding sites on the antibody molecules of sheep antiserum. To obtain the binding parameters, binding constant (K) and number of independent binding site (n), generally, Scatchard equation is used. This Scatchard equation is expressed in the concentration terms of free drug, bound drug, and protein (antibody). The binding parameters can not be obtained by applying the TDxFLx calibration data to the Scatchard equation directly because the TDxFLx calibration data are composed of the fluorescence polarization and the total drug concentrations. To obtain the binding parameters from the TDxFLx calibration data the new useful equation which was expressed in the total concentrations of drug and fluorescence polarization should be derived. Derivation of new equation was based on the Scatchard equation. The TDxFLx calibration data was curve fitted to the derived equation using KaleidaGraph program and Macintosh computer. The binding constant (K) and the number (n(P(t))) of binding site of 11-nor-delta(9)-tetrahydrocannabinol-9-carboxylic acid (COOH.THC) on the antibody were 1.14 x 10(8)l/mole and 4.04 x 10(-7)M, respectively. The binding constant and the number (n(P(t))) of binding site of amphetamine were 5.15 x 10(5)l/mole and 2.05 x 10(6)M, respectively. In case of COOH.THC the fluorescence polarization decreased linearly with the concentration. However, in case of amphetamine or the other three abused drugs the fluorescence polarizations decreased exponentially with their concentrations.
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PMID:Interpretations of the TDxFLx calibration data of the abused drugs. 1250 64