Publications by authors named "Risa Taguchi"
Article Synopsis
- Sialidase is crucial for long-term potentiation and spatial memory, facilitating the removal of sialic acids from cell surfaces in response to neural activity.
- Increased sialidase activity linked to high-K-induced depolarization and chemical stimulation indicates a shift in sialidase localization rather than increased expression.
- High-frequency stimulation in hippocampal slices shows immediate desialylation, suggesting that sialidase plays a key role in the neural processes underlying memory formation.
The two main molecular species of sialic acid existing in nature are N-acetylneuraminic acid (Neu5Ac) and N-glycolylneuraminic acid (Neu5Gc). Neu5Ac is abundant in mammalian brains and plays crucial roles in many neural functions. In contrast, Neu5Gc is present only at a trace level in vertebrate brains.
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- Sialidase is an enzyme that removes sialic acid from specific molecules and is linked to important processes in cancer development.
- Researchers have created a new fluorescent substrate, BTP-Neu5Ac, that allows for sensitive visualization of sialidase activity in living tissues, particularly useful in studying brain slices and human colon cancers.
- The findings indicate that BTP-Neu5Ac could be a valuable tool for imaging sialidase activities, aiding in cancer diagnosis and research.
In a comparison of sialidase activities toward N-acetylneuraminic acid (Neu5Ac) and N-glycolylneuraminic acid (Neu5Gc), we found that Salmonella typhimurium LT2 sialidase (STSA) hardly cleaved 4-methylumbelliferyl Neu5Gc (4MU-Neu5Gc). The k cat/K m value of STSA for 4MU-Neu5Gc was found to be 110 times lower than that for 4-methylumbelliferyl Neu5Ac (4MU-Neu5Ac). Additionally, STSA had remarkably weak ability to cleave α2-3-linked-Neu5Gc contained in gangliosides and equine erythrocytes.
View Article and Find Full Text PDF2-(Benzothiazol-2-yl)-phenyl-β-d-galactopyranoside derivatives were synthesized as novel artificial fluorescent pigment dyeing substrates for β-d-galactosidase. The substrates, which exhibited non-fluorescence or weak fluorescence in solution phase, were smoothly hydrolyzed by β-d-galactosidase from Aspergillus oryzae and yielded a water-insoluble strong fluorescent pigment. The difference of fluorescent intensity exhibited a linear relationship with the amount of enzyme.
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