Lysosomal inherited disorders - pathobiochemistry of the Gaucher disease

Gaucher disease is one of the lysosomal storage disorders belonging to inherited defects of catabolism of sphingolipids. These defects are caused by mutation in genes of sphingolipid hydrolases or their protein activators. Subsequent storage of non-degraded sphingolipids leads to severe clinical phenotypes in patients. Gaucher disease is caused by deficiency of lysosomal β-glucocerebrosidase (GBA1) activity. Non-degraded glycosphingolipids are glucosylceramide (GlcCer) and glucosylpsychosine (lyso-GlcCer). Accumulation of these glycosphingolipids is related to Gaucher cells which are derived from macrophages and are abundant in spleen, liver or lung. The objective of the diploma thesis is pathobiochemistry of above mentioned glycosphingolipids. One of the topics of this work was optimization of mass spectrometry method for determination of activity of lysosomal β-glucocerebrosidase, using a natural substrate. The method was successfully optimized and can be effectively used for diagnostic purpose, instead of methods utilizing artificial substrates. In the next step, we performed analysis of pH profiles of lysosomal β-glucocerebrosidase activity focusing to search for non-lysosomal enzyme, which is able to degrade glucosylceramide. Evaluation of pH profiles did not confirm the existence of such an..