Biochemical Studies in Cat and Human Gangliosidosis1, 2

The biochemical analysis of the hereditary neurological disease found in a family of Siamese cat is reported. The accumulation of GM1ganglioside in the brain was noted. Several glycosidase activities of these cat brains were compared with that of human gangliosidoses (Tay‐Sachs disease and GM1‐gangliosidosis). Glycosidase activities were estimated using ρ‐nitrophenyl‐glycosides, glucosyl‐, galactosyl‐ceramide and GM1‐ganglioside as substrates. The results indicated the defect of the β‐galactosidase activities for the ρ‐nitrophenyl‐β‐galactoside and GM1‐ganglioside in both cat and human GM1‐gangliosidoses. Glycosidase activities for glucosyl‐ and galactosyl‐ceramide were not changed in either gangliosidoses.