title: An HPLC assay for detection of elevated urinary S-sulphocysteine, a metabolic marker of sulphite oxidase deficiency.
abstract: Sulphite oxidase deficiency occurs in man in two forms, as the isolated deficiency and as a syndrome of combined molybdoenzyme deficiency. This latter pleiotropic condition has as its underlying cause a defect in the synthesis of the molybdenum cofactor required for the activity of all molybdoenzymes in humans. Difficulties in diagnosis of sulphite oxidase deficiency are often encountered. A new method for detection of a key diagnostic metabolite, S-sulphocysteine, is outlined. The procedure is based on precolumn derivatization of urinary amino acids with dimethylaminoazobenzene sulphonyl chloride (Dabsyl-Cl) and resolution of the modified S-sulphocysteine by reversed-phase HPLC. A number of affected patients and control individuals with similar clinical symptoms have been studied, and a clear demarcation between the two groups has been noted.
authors.affiliation: Department of Biochemistry, Duke University Medical Center, Durham, North Carolina 27710, USA.
authors.forename: J L
authors.initials: JL
authors.lastname: Johnson
authors.forename: K V
authors.initials: KV
authors.lastname: Rajagopalan
mesh_terms: D000596:Amino Acids / Q000652:urine; D015415:Biomarkers / Q000652:urine; D002851:Chromatography, High Pressure Liquid; D003067:Coenzymes / Q000378:metabolism; D003545:Cysteine / Q000031:analogs & derivatives* / Q000652:urine; D006801:Humans; D008661:Metabolism, Inborn Errors / Q000175:diagnosis / Q000652:urine*; D008667:Metalloproteins / Q000378:metabolism; D008982:Molybdenum / Q000378:metabolism; D000090006:Molybdenum Cofactors; D050862:Oxidoreductases Acting on Sulfur Group Donors / Q000172:deficiency*; D011621:Pteridines / Q000378:metabolism; D013654:Taurine / Q000652:urine
chemical_list: D000596:Amino Acids; D015415:Biomarkers; D003067:Coenzymes; D003545:Cysteine; D008667:Metalloproteins; D008982:Molybdenum; D000090006:Molybdenum Cofactors; D050862:Oxidoreductases Acting on Sulfur Group Donors; D011621:Pteridines; D013654:Taurine; C011119:S-sulphocysteine; C022261:molybdopterin