Читать книгу Cell Biology - Stephen R. Bolsover - Страница 47

A number of inherited diseases are characterized by cells filled with very large lysosomes. Many of these diseases involve abnormalities of development of the skeleton and connective tissues, as well as of the nervous system. The severity varies with the particular disease, but they often lead to death in infancy. In the majority of these diseases one lysosomal enzyme is missing or defective. Lysosomes work to degrade cellular components that are damaged or no longer needed and their enzymes function under the acidic conditions in the lysosome. If one of these enzymes is defective then the substrate will accumulate, filling the lysosome. The distended lysosomes eventually fill and damage the cell. Some of the best understood lysosomal storage diseases involve deficiencies in one or other of the enzymes required to degrade the complex glycosylated proteins and lipids found on cell surfaces.

Tay‐Sachs disease involves severe mental retardation and blindness, with death by the age of three. In this case an enzyme required to break down a particular complex membrane lipid called a ganglioside is missing and undegraded ganglioside accumulates, swelling the lysosomes. Gangliosides are especially important in neuronal membranes so neurons are particularly damaged.