Toshinori Sato

Ethylene is the plant hormone that controls several features of plant growth and development. The rate-limiting step in its synthesis is the formation of the ethylene precursor 1-aminocyclopropane-1-carboxylic acid (ACC) from S-adenosylmethionine (AdoMet), catalyzed by ACC synthase. We have isolated a complementary DNA sequence encoding ACC synthase from zucchini (Cucurbita) fruits. The biological activity of the clone was confirmed by the ability of the cloned sequence to direct ACC synthase ac

Insertion of the plug was possible in all except two ears, in which it failed because of a narrow tympanic orifice of the ET. In 11 ears of 10 patients, the plug was replaced by a larger one using the same approach to improve efficacy. Of the 42 ears in which the silicone plug was successfully inserted, 30 (71.4%) achieved relief from symptoms of PET without additional treatment. In > 60% of these cases, the symptoms of PET were well controlled with an aerated middle ear. The follow-up period ra

The key regulatory enzyme in the biosynthetic pathway of the plant hormone ethylene is 1-aminocyclopropane-1-carboxylic acid (ACC) synthase (EC 4.4.1.14). We have partially purified ACC synthase 6,000-fold from Cucurbita fruit tissue treated with indoleacetic acid + benzyladenine + aminooxyacetic acid + LiCl. The enzyme has a specific activity of 35,000 nmol/h/mg protein, a pH optimum of 9.5, an isoelectric point of 5.0, a Km of 17 microM with respect to S-adenosylmethionine, and is a dimer of t

Ganglioside Gal beta1 --> 3GalNAc beta1 --> 4(NeuAc alpha2 --> 3) Gal beta1 --> 4Glc beta1 -->1'Cer (GM1)-binding peptides were obtained from a phage-displayed pentadecapeptide library by an affinity selection. The selection processes were in situ-monitored by a quartz-crystal microbalance method, on which a ganglioside GM1 monolayer was transferred. After five rounds of biopanning, the DNA sequencing of 18 selected phages showed that only three individual clones were selected. The peptide seque

Some protein and peptide aggregates, such as those of amyloid-β protein (Aβ), are neurotoxic and have been implicated in several neurodegenerative diseases. Aβ accumulates at nanoclusters enriched in neuronal lipids called gangliosides in the presynaptic neuronal membrane, and the resulting oligomeric and/or fibrous forms accelerate the development of Alzheimer's disease. Although the presence of Aβ deposits at such nanoclusters is known, the mechanism of their assembly and the relationship betw

A convenient method for distinguishing underivatized isomeric monosaccharides has been established using electrospray ionization ion trap mass spectrometry (ESI-ITMS). Mass spectra of hexoses (glucose, galactose, and mannose), N-acetylhexosamines (N-acetylglucosamine, N-acetylgalactosamine, and N-acetylmannosamine) and hexosamines (glucosamine, galactosamine, and mannosamine) dissolved in solvent containing 1 mM ammonium acetate were obtained in the positive ion mode. Glucose was distinguished f

The development of a simple detection method with high sensitivity is essential for the diagnosis and surveillance of infectious diseases. Previously, we constructed a sensitive biosensor for the detection of pathological human influenza viruses using a boron-doped diamond electrode terminated with a sialyloligosaccharide receptor-mimic peptide that could bind to hemagglutinins involved in viral infection. Circulation of influenza induced by the avian virus in humans has become a major public he