Biochemical characterization of chitotriosidase enzyme: comparison between normal individuals and patients with Gaucher and with Niemann-Pick diseases.
OBJECTIVE
The aim of the present study was to establish the range of chitotriosidase (CT) activity in normal individuals, patients with Gaucher disease (GD) and Niemann-Pick disease (NPD), types A or B. The kinetics of CT in these three groups was also investigated.


METHODS
CT activity, as well as Km, Vmax, optimum pH, and thermal stability of the enzyme were determined in the plasma of control, GD, and NPD subjects.


RESULTS
CT activity in GD and NPD patients was, respectively, around 600-fold and 30-fold greater than in normal individuals. We observed significant differences in optimum pH, Vmax, and thermal stability between the various groups. Km was different in normal individuals relative to GD and NPD patients. However, there was no significant difference between Km values in patients with GD and with NPD.


CONCLUSIONS
Based on the differences found in the biochemical parameters studied, our results may be important to help the identification of patients not only with GD but also with NPD.
Wajner
Alessandro
A
Departamento de Bioquímica, ICBS, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil.
Michelin
Kristiane
K
Burin
Maira G
MG
Pires
Ricardo F
RF
Pereira
Maria Luiza S
ML
Giugliani
Roberto
R
Coelho
Janice C
JC
D001681:Biological Assay / Q000379:methods; D001800:Blood Specimen Collection / Q000379:methods; D016022:Case-Control Studies; D004795:Enzyme Stability; D005776:Gaucher Disease / Q000201:enzymology*; D018882:Heat Stress Disorders; D006596:Hexosaminidases / Q000097:blood*; D006801:Humans; D006863:Hydrogen-Ion Concentration; D009542:Niemann-Pick Diseases / Q000201:enzymology*
D006596:Hexosaminidases; C086400:chitotriosidase