No abstract

To develop a novel enzyme replacement therapy for neurodegenerative Tay-Sachs disease (TSD) and Sandhoff disease (SD), which are caused by deficiency of β-hexosaminidase (Hex) A, we designed a genetically engineered HEXB encoding the chimeric human β-subunit containing partial amino acid sequence of the α-subunit by structure-based homology modeling. We succeeded in producing the modified HexB by a Chinese hamster ovary (CHO) cell line stably expressing the chimeric HEXB, which can degrade artificial anionic substrates and GM2 ganglioside in vitro, and also retain the wild-type (WT) HexB-like thermostability in the presence of plasma. The modified HexB was efficiently incorporated via cation-independent mannose 6-phosphate receptor into fibroblasts derived from Tay-Sachs patients, and reduced the GM2 ganglioside accumulated in the cultured cells. Furthermore, intracerebroventricular administration of the modified HexB to Sandhoff mode mice restored the Hex activity in the brains, and reduced the GM2 ganglioside storage in the parenchyma. These results suggest that the intracerebroventricular enzyme replacement therapy involving the modified HexB should be more effective for Tay-Sachs and Sandhoff than that utilizing the HexA, especially as a low-antigenic enzyme replacement therapy for Tay-Sachs patients who have endogenous WT HexB.

No abstract

Fabry disease is a genetic disorder caused by a deficiency of a-galactosidase A (GLA). In our previous studies, we structurally investigated Fabry disease using a structural analysis system, and revealed that structural changes in GLA are very important for understanding the molecular basis of this disease. To the best of our knowledge, there is no database including the structures of mutant GLAs. Herein, we constructed a database of clinical phenotypes, genotypes and structures of mutant GLAs. This database can be accessed as 'fabry-database.org', and is user friendly, being equipped with powerful computational tools. This database will help researchers and clinicians who study Fabry disease.