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Stanley Fahn - One of the best experts on this subject based on the ideXlab platform.
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Dopamine Beta-Hydroxylase activity in cerebrospinal fluid of idiopathic torsion dystonia.
Neurology, 1990Co-Authors: D. H. Park, Un Jung Kang, Carol Moskowitz, Robert E. Burke, Tong H. Joh, Stanley FahnAbstract:Since a postmortem biochemical study and a genetic linkage study of idiopathic torsion dystonia suggested possible involvement of Dopamine Beta-Hydroxylase (DBH), we determined CSF DBH activities of Jewish and non-Jewish patients with childhood-onset idiopathic torsion dystonia and found no differences from a control population.
D. H. Park - One of the best experts on this subject based on the ideXlab platform.
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Dopamine Beta-Hydroxylase activity in cerebrospinal fluid of idiopathic torsion dystonia.
Neurology, 1990Co-Authors: D. H. Park, Un Jung Kang, Carol Moskowitz, Robert E. Burke, Tong H. Joh, Stanley FahnAbstract:Since a postmortem biochemical study and a genetic linkage study of idiopathic torsion dystonia suggested possible involvement of Dopamine Beta-Hydroxylase (DBH), we determined CSF DBH activities of Jewish and non-Jewish patients with childhood-onset idiopathic torsion dystonia and found no differences from a control population.
P J Fleming - One of the best experts on this subject based on the ideXlab platform.
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Expression of Dopamine Beta-Hydroxylase in Drosophila Schneider 2 cells. Evidence for a mechanism of membrane binding other than uncleaved signal peptide.
The Journal of biological chemistry, 1993Co-Authors: K R Gibson, P G Vanek, W D Kaloss, G B Collier, J F Connaughton, M Angelichio, G P Livi, P J FlemingAbstract:Abstract To characterize the mechanism of membrane attachment of Dopamine Beta-Hydroxylase, an expression system producing the processed form of this enzyme has been developed. We have replaced the endogenous signal peptide of bovine Dopamine Beta-Hydroxylase with a heterologous signal peptide which is efficiently recognized and cleaved in Drosophila Schneider 2 cells. A cDNA encoding this chimeric recombinant bovine enzyme has been stably transfected into Schneider 2 cells. The inducible expression of active Dopamine Beta-Hydroxylase in these cells has been verified by Western blotting and enzyme activity assays. N-terminal sequence analysis of purified recombinant enzyme demonstrates complete removal of the signal peptide. Subcellular analysis shows that the recombinant enzyme exists as both a soluble and a membrane-bound form in these cells. These data demonstrate that the endogenous signal peptide is not required for the formation of the membranous Dopamine Beta-Hydroxylase and further that the enzyme can be bound to membranes via a mechanism other than uncleaved signal sequence.
Elaine J. Lewis - One of the best experts on this subject based on the ideXlab platform.
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Soluble and membrane-bound forms of Dopamine Beta-Hydroxylase are encoded by the same mRNA.
The Journal of biological chemistry, 1992Co-Authors: Elaine J. Lewis, L P AsnaniAbstract:Abstract A full length cDNA clone for bovine Dopamine Beta-Hydroxylase was expressed in rat pheochromocytoma PC12 cells by stable transformation of this cell line with a plasmid expression vector. The recombinant protein exhibited Dopamine Beta-Hydroxylase enzyme activity and was found in both the soluble and membrane fractions of the secretory vesicle. Immunoprecipitation of cell extracts from recombinant cell lines with Dopamine Beta-Hydroxylase antisera followed by fractionation on sodium dodecyl sulfate-polyacrylamide gel electrophoresis revealed two subunits, which migrated to relative molecular masses of 76 and 78 kDa. The recombinant protein co-fractionated with neurotransmitter when subcellular structures were separated by sucrose gradient density centrifugation, suggesting that the protein was routed to the secretory vesicles. Dopamine Beta-Hydroxylase immunoreactivity in those sucrose gradient fractions presumed to contain secretory vesicles was resistant to treatment with trypsin unless the nonionic detergent Triton X-100 was also present to disrupt membrane structure. The 76- and 78-kDa isoform were each found in both the membrane and soluble fractions of the secretory vesicle. Treatment of cultured cells with nerve growth factor or 8-(4-chlorophenylthio)-cyclic AMP alters the relative distribution of the subunits such that the 76-kDa form predominates. The subcellular distribution of a Dopamine Beta-Hydroxylase cDNA clone lacking the first 16 nucleotide residues was also determined. The predicted amino acid sequence of the protein encoded by this cDNA would be deleted of the first 13 residues of the signal sequence, which were reported to be present in the membrane-bound form, but not the soluble form, of native Dopamine Beta-Hydroxylase (Taljanidisz, J., Stewart, L., Smith, A. J., and Klinman, J. P. (1989) Biochemistry 28, 10054-10061). Immunoprecipitable Dopamine Beta-Hydroxylase derived from expression of the deleted cDNA was found in both the membrane-bound and soluble fractions of the secretory vesicle. These experiments demonstrate that the membrane-bound and soluble forms of Dopamine Beta-Hydroxylase are derived from one primary translation product, which is also sufficient to produce enzyme activity. In addition, the amino-terminal amino acids encoding residues 1-13, which compose the hydrophilic region of the signal sequence, are not necessary for the biogenesis of membrane-bound Dopamine Beta-Hydroxylase.
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Bovine Dopamine Beta-Hydroxylase cDNA. Complete coding sequence and expression in mammalian cells with vaccinia virus vector.
The Journal of biological chemistry, 1990Co-Authors: Elaine J. Lewis, S Allison, D Fader, V Claflin, L BaizerAbstract:We have isolated cDNA clones for bovine Dopamine Beta-Hydroxylase from an adrenal medulla cDNA library and have determined the complete coding sequence. The largest cDNA clone isolated from the library is 2.4 kilobase pairs (kb) and contains an open reading frame of 1788 bases, coding for a protein of 597 amino acids and Mr = 66,803. The predicted amino acid sequence of the bovine cDNA contains 85% identity with human Dopamine Beta-Hydroxylase (Lamouroux, A., Vingny, A., Faucon Biquet, N., Darmon, M. C., Franck, R., Henry, J.P., and Mallet, J. (1987) EMBO J. 6, 3931-3937; Kobayashi, K., Kurosawa, Y., Fujita, K., and Nagatsu, T. (1989) Nucleic Acids Res. 17, 1089-1102). Northern blot analysis reveals that the cDNA hybridizes to an mRNA of 2.4 kb present in bovine adrenal medulla, but not in kidney, heart, or liver. In addition, the cDNA hybridizes to a second RNA species of 5.5 kb, which is 4-fold less abundant than the 2.4-kb RNA. In vitro translation of a synthetic RNA transcribed from the 2.4-kb cDNA produces a 68-kDa protein, which is specifically immunoprecipitated by antiserum to bovine Dopamine Beta-Hydroxylase. The 2.4-kb cDNA was cloned into a vaccinia virus vector, and the recombinant virus was used to infect the rat pheochromocytoma PC12 and monkey BSC-40 fibroblast cell lines. In both cell lines, infection with recombinant virus produces a protein of Mr = 75,000, which reacts with antiserum to bovine Dopamine Beta-Hydroxylase. These results indicate that the 2.4-kb cDNA contains the genetic information necessary to code for the bovine Dopamine Beta-Hydroxylase subunit.
M Réglier - One of the best experts on this subject based on the ideXlab platform.
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Dopamine Beta-Hydroxylase inactivation generates a protein-bound quinone derivative.
FEBS letters, 2001Co-Authors: P Slama, F Jabre, T Tron, M RéglierAbstract:Bovine Dopamine Beta-Hydroxylase (DbH) was inactivated by hydrogen peroxide and ascorbate in the presence of dioxygen. Both inactivated forms of the enzyme were investigated. We could highlight the presence of a quinone derivative bound to the protein, assumed as being dopa-quinone, that is absent from active enzyme. Such results suggest that a tyrosinyl radical transiently forms during catalysis. Moreover we could show that addition of substrate tyramine to H2O2 incubates is responsible for a partial protection of DbH against inactivation.
