title: Substrate inhibition of lysosomal hydrolases: α-Galactosidase A and β-glucocerebrosidase.
abstract: OBJECTIVE
  We have investigated the kinetics of α-galactosidase A and β-glucocerebrosidase deficient in Fabry and Gaucher diseases, respectively.
  
  
  METHODS
  We have performed spectrofluorymetric measurements of the activity of enzymes using a derivative of 4-methylumbelliferone as a substrate and a human T-cell line as a source of enzymes.
  
  
  RESULTS
  We have observed the substrate inhibition effect, which is related to temperature.
  
  
  CONCLUSIONS
  The diagnostic procedures for Fabry and Gaucher diseases used now in laboratory practice neglect temperature-dependent substrate inhibition, which may significantly reduce the sensitivity of enzyme activity determinations.
authors.affiliation: Department of Microbioanalytics, Institute of Biotechnology, Warsaw University of Technology, Warsaw, Poland.
authors.forename: Radoslaw
authors.initials: R
authors.lastname: Kwapiszewski
authors.forename: Barbara
authors.initials: B
authors.lastname: Czartoryska
authors.forename: Karina
authors.initials: K
authors.lastname: Ziolkowska
authors.forename: Michal
authors.initials: M
authors.lastname: Chudy
authors.forename: Artur
authors.initials: A
authors.lastname: Dybko
authors.forename: Zbigniew
authors.initials: Z
authors.lastname: Brzozka
mesh_terms: D055162:Biocatalysis; D005962:Glucosylceramidase / Q000378:metabolism*; D006801:Humans; D006923:Hymecromone / Q000031:analogs & derivatives* / Q000037:antagonists & inhibitors / Q000378:metabolism; D019169:Jurkat Cells; D008247:Lysosomes / Q000201:enzymology*; D013379:Substrate Specificity; D013696:Temperature; D000519:alpha-Galactosidase / Q000378:metabolism*
chemical_list: D006923:Hymecromone; D000519:alpha-Galactosidase; D005962:Glucosylceramidase