Identification of Chitotriosidase Isoforms in Plasma of Gaucher Disease Patients by Two Dimensional Gel Electrophoresis.

Introduction: Chitotriosidase protein (CT) is the most important biochemical marker described for Gaucher disease (GD). CT activity is increased several hundred-fold in plasma of GD patients and shows a strong positive correlation with the severity of the disease. However, a recessively inherited enzyme deficiency, with an incidence of about 6% in the Caucasian population, means that not all patients with GD can be monitored by measuring CT activity.

Materials and Methods: This study was performed with plasma samples from 22 type 1 GD patients and 23 healthy subjects. All patients are from Spanish GD Registry. Applying two dimensional gel electrophoresis (2-DE) we compared the plasma proteome profile of GD patients with that of healthy subjects. Differential proteins were excised and prepared for MALDI-TOF analysis. Results were verify with 2-DE western blot.

Results: In this study we have described five CT isoforms in a 2-DE gel from GD plasma samples. We show and compare the 2-DE images of each CT spot in plasma protein samples from healthy controls, GD patients with wild-type CT protein, and GD patients either homozygous or heterozygous for the 24 bp duplication. We propose a connection between the quantitative image analysis of each CT spot and the enzymatic activity of CT in each patient. Lastly, our results verifies that post-translational glycosylation explains at least some of differences between CT isoforms.

Conclusion: The possibilities of proteomic technology in the investigation of biological biomarkers of GD and the nature of the CT protein are demonstrated, as well as in detecting new biochemical markers useful for the diagnosis of the disease and for monitoring patient response to therapy.