99 research outputs found
Etablierung und Optimierung von in vivo- und in vitro-Systemen zur Erhöhung der Produktion sowie zur Stabilisierung der humanen Dopaminrezeptoren D2 und D3
Optimizing the Expression of Human Dopamine Receptors in Escherichia coli
The human dopamine receptors D2S and D3 belong to the group of G protein-coupled receptors (GPCRs) and are important drug targets. Structural analyses and development of new receptor subtype specific drugs have been impeded by low expression yields or receptor instability. Fusing the T4 lysozyme into the intracellular loop 3 improves crystallization but complicates conformational studies. To circumvent these problems, we expressed the human D2S and D3 receptors in Escherichia coli using different N- and C-terminal fusion proteins and thermostabilizing mutations. We optimized expression times and used radioligand binding assays with whole cells and membrane homogenates to evaluate KD-values and the number of receptors in the cell membrane. We show that the presence but not the type of a C-terminal fusion protein is important. Bacteria expressing receptors capable of ligand binding can be selected using FACS analysis and a fluorescently labeled ligand. Improved receptor variants can thus be generated using error-prone PCR. Subsequent analysis of clones showed the distribution of mutations over the whole gene. Repeated cycles of PCR and FACS can be applied for selecting highly expressing receptor variants with high affinity ligand binding, which in the future can be used for analytical studies
2-Phenyl-1,3-selenazole-4-carbÂoxyÂlic acid
In the title compound, C10H7NO2Se, the two rings are twisted, making a dihedral angle of 12.42 (9)°. In the crystal, pairs of molÂecules are disposed about an inversion center, generating O—H⋯O hydrogen-bonded dimers
Membrane Transport Properties and Biological Activity of Stereo-isomers of Glycinamide Ribonucleotide Formyltransferase (GARFT) Inhibitors AG2032 and AG2034
Identification of the major lesion from the reaction of an acridine targeted aniline mustard with DNA as an adenine N1 adduct
A convenient one-pot synthesis of 2,5-anhydro-3,4,6-tri-O-benzoyl-D-[1-14C]allononitrile, and its conversion to methyl 2-β-D-ribofuranosyl-4-[2-14C]selenazolecarboxylate
A synthesis of 2-β-D-ribofuranosyl-4-selenazolecarboxamide (selenazofurin) and certain N
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