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Applications of a new fluorimetric enzyme assay for the diagnosis of aspartylglucosaminuria
Author(s) -
Vozyi Ya. V.,
Keulemans J. L. M.,
Lleijer W. J.,
Aula P.,
Gray G. R.,
Diggelen O. P.
Publication year - 1993
Publication title -
journal of inherited metabolic disease
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.462
H-Index - 102
eISSN - 1573-2665
pISSN - 0141-8955
DOI - 10.1007/bf00711507
Subject(s) - amniotic fluid , chorionic villi , enzyme , substrate (aquarium) , enzyme assay , chemistry , substrate specificity , biochemistry , microbiology and biotechnology , prenatal diagnosis , fetus , biology , pregnancy , genetics , ecology
Summary L ‐Aspartic acid‐β‐7‐amido‐4‐methylcoumarin is a sensitive and specific fluorogenic substrate for lysosomal glycoasparaginase (aspartylgluco‐saminidase). 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. β‐Aspartyl‐4‐methylumbelliferone was synthesized but this potential substrate can not be used to assay glycoasparaginase since it hydrolyses spontaneously.