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Nishi-Tokyo-shi, Japan

Matsuoka K.,Tokushima University | Matsuoka K.,Japan Science and Technology Agency | Tsuji D.,Tokushima University | Tsuji D.,Japan Science and Technology Agency | And 8 more authors.
Molecular Therapy | Year: 2010

Human lysosomal Β-hexosaminidase A is a heterodimer composed of α-and Β-subunits encoded by HEXA and HEXB, respectively. We genetically introduced an additional N-glycosylation sequon into HEXA, which caused amino acid substitutions (S51 to N and A53 to T) at homologous positions to N84 and T86 in the Β-subunit. The mutant HexA (NgHexA) obtained from a Chinese hamster ovary (CHO) cell line co-expressing the mutated HEXA and wild-type HEXB complementary DNAs was demonstrated to contain an additional mannose-6-phosphate (M6P)-type-N-glycan. NgHexA was more efficiently taken up than the wild-type HexA and delivered to lysosomes, where it degraded accumulated substrates including GM2 ganglioside (GM2) when administered to cultured fibroblasts derived from a Sandhoff disease (SD) patient. On intracerebroventricular (i.c.v.) administration of NgHexA to SD model mice, NgHexA more efficiently restored the HexA activity and reduced the GM2 and GA2 (asialoGM2) accumulated in neural cells of the brain parenchyma than the wild-type HexA. These findings indicate that i.c.v. administration of the modified human HexA with an additional M6P-type N-glycan is applicable for enzyme replacement therapy (ERT) involving an M6P-receptor as a molecular target for HexA deficiencies including Tay-Sachs disease and SD. © The American Society of Gene & Cell Therapy. Source

Rahman M.M.,Tokushima University | Kitao S.,Tokushima University | Tsuji D.,Tokushima University | Tsuji D.,Agri Health Translational Research Project No 5130 Of The Ministry Of Agriculture | And 7 more authors.
Glycobiology | Year: 2013

Human sialidase 2 (NEU2) is a cytoplasmic sialidase that degrades sialylglycoconjugates, including glycoproteins and gangliosides, via hydrolysis of terminal sialic acids to produce asialo-type molecules. Here, we first report the inhibitory effects of a series of synthetic sialyldendrimers comprising three types [Dumbbell(1)6-S-Neu5Ac6, Fan(0)3-S-Neu5Ac3 and Ball(0)4-S-NeuAc4] toward recombinant human NEU2 in vitro. Among them, Dumbbell(1)6-S-Neu5Ac6 exhibited the most potent inhibitory activity (concentration causing 50% inhibition (IC50), 0.4 ∼ 0.5 mM). In addition, NeuSLac and NeuSCel carrying thiosialyltrisaccharide moieties exhibited more potent inhibitory effects than NeuSGal and NeuSGlc carrying thiosialyldisaccharides. Docking models composed of NEU2 and the thiosialyloligosaccharide suggested that the active pocket of NEU2 prefers the second galactose-ß (Galß) to the glucose-ß (Glcß) residue in the trisaccharide structure, there being a hydrogen bond between the 4-hydroxy group of the second Galß and the side chain of the D46 residue of NEU2. The third Glcß residues of NeuSLac and NeuSCel were also predicted to be stabilized by hydrogen bonds with the side chains of the R21, R304, D358 and Y359 residues of NEU2. NEU2 mutants (D358A and Y359A) exhibited reduced affinity for NeuSLac carrying thiosialyltrisaccharide moieties, suggesting the significant roles of D358 and Y359 residues in recognition of thiosialyltrisaccharide moieties of NeuSLac bound in the active pocket of NEU2. Thus, the present sialyldendrimers could be utilized not only as a new class of NEU2 inhibitors but also as molecular probes for evaluating the biological functions of NEU2, including the catalytic activity and mechanism as to natural substrates carrying sialyloligosaccharides. © 2013 The Author 2013. Published by Oxford University Press. All rights reserved. Source

Altif Laboratories Inc. and Tokyo Metropolitan Institute of Medical Science | Date: 2013-09-13

The present invention provides a pharmaceutical composition comprising a protein having -galactosidase activity for treating Fabry disease, which causes no allergic side effect, which is highly stable in blood (plasma) and which can readily be taken up by a cell of an affected organ. The pharmaceutical composition for treating Fabry disease of the invention comprises, for example, a protein which acquires an -galactosidase activity through alteration of the structure of the active site of wild-type human -N-acetylgalactosaminidase.

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