title: Applications of a new fluorimetric enzyme assay for the diagnosis of aspartylglucosaminuria.
abstract: L-Aspartic acid-beta-7-amido-4-methylcoumarin is a sensitive and specific fluorogenic substrate for lysosomal glycoasparaginase (aspartylglucosaminidase). Fibroblasts and leukocytes from 8 patients with aspartylglucosaminuria, showed 1-7% of the mean normal glycoasparaginase activity. Heterozygotes showed intermediate activities. Glycoasparaginase activity in chorionic villi, cultured trophoblasts, cultured amniotic fluid cells and amniotic fluid was readily detectable, indicating that prenatal analysis of aspartylglucosaminuria should be possible with this assay. beta-Aspartyl-4-methylumbelliferone was synthesized but this potential substrate can not be used to assay glycoasparaginase since it hydrolyses spontaneously.
authors.affiliation: Department of Chemistry, University of Minnesota, Minneapolis.
authors.lastname: Voznyi YaV
authors.forename: J L
authors.initials: JL
authors.lastname: Keulemans
authors.forename: W J
authors.initials: WJ
authors.lastname: Kleijer
authors.forename: P
authors.initials: P
authors.lastname: Aula
authors.forename: G R
authors.initials: GR
authors.lastname: Gray
authors.forename: O P
authors.initials: OP
authors.lastname: van Diggelen
mesh_terms: D000117:Acetylglucosamine / Q000031:analogs & derivatives* / Q000652:urine; D000592:Amino Acid Metabolism, Inborn Errors / Q000175:diagnosis / Q000201:enzymology / Q000652:urine*; D000653:Amniotic Fluid / Q000201:enzymology; D001227:Aspartylglucosylaminase / Q000032:analysis*; D002824:Chorionic Villi / Q000201:enzymology; D005260:Female; D005347:Fibroblasts / Q000201:enzymology; D005470:Fluorometry; D006580:Genetic Carrier Screening; D006801:Humans; D007962:Leukocytes / Q000201:enzymology; D011247:Pregnancy; D011296:Prenatal Diagnosis / Q000379:methods; D013379:Substrate Specificity
chemical_list: C000009:N-acetylglucosaminylasparagine; D001227:Aspartylglucosylaminase; D000117:Acetylglucosamine