Studies from Cornell University, Department of Nutritional Sciences have provided new information about biological chemistry
2007 OCT 8 -- New research, 'Discovery and characterization of a second mammalian thiol dioxygenase, cysteamine dioxygenase,' is the subject of a report. According to a study from the United States, "There are only two known thiol dioxygenase activities in mammals, and they are ascribed to the enzymes cysteine dioxygenase (CDO) and cysteamine (2-aminoethanethiol) dioxygenase (ADO). Although many studies have been dedicated to CDO, resulting in the identification of its gene and even characterization of the tertiary structure of the protein, relatively little is known about cysteamine dioxygenase." "The failure to identify the gene for this protein has significantly hampered our understanding of the metabolism of cysteamine, a product of the constitutive degradation of coenzyme A, and the synthesis of taurine, the final product of cysteamine oxidation and the second most abundant amino acid in mammalian tissues. In this study we identified a hypothetical murine protein homolog of CDO (hereafter called ADO) that is encoded by the gene Gm237 and belongs to the DUF1637 protein family. When expressed as a recombinant protein, ADO exhibited significant cysteamine dioxygenase activity in vitro. The reaction was highly specific for cysteamine; cysteine was not oxidized by the enzyme, and structurally related compounds were not competitive inhibitors of the reaction. When overexpressed in HepG2/C3A cells, ADO increased the production of hypotaurine from cysteamine. Similarly, when endogenous expression of the human ADO ortholog C10orf22 in HepG2/C3A cells was reduced by RNA-mediated interference, hypotaurine production decreased. Western blots of murine tissues with an antibody developed against ADO showed that the protein is ubiquitously expressed with the highest levels in brain, heart, and skeletal muscle," wrote J.E. Dominy and colleagues, Cornell University, Department of Nutritional Sciences. The researchers concluded: "Overall, these data suggest that ADO is responsible for endogenous cysteamine dioxygenase activity.'." Dominy and colleagues published the results of their research in the Journal of Biological Chemistry (Discovery and characterization of a second mammalian thiol dioxygenase, cysteamine dioxygenase. Journal of Biological Chemistry, 2007;282(35):25189-98). For additional information, contact J.E. Dominy, Cornell University, Dept. of Nutritional Sciences, Ithaca, New York 14853 USA.. The publisher of the Journal of Biological Chemistry can be contacted at: American Society Biochemistry Molecular Biology Inc., 9650 Rockville Pike, Bethesda, MD 20814-3996, USA. Keywords: United States, Ithaca, Biological Chemistry, Cysteamine, Dioxygenase, Enzyme Research, Nephropathic Cystinosis Therapy, Radiation-Protective Agent. This article was prepared by Biotech Business Week editors from staff and other reports. Copyright 2007, Biotech Business Week via NewsRx.com.
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