Takeshi Tsumuraya

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Ciguatoxins are the major causative toxins of ciguatera seafood poisoning. Limited availability of ciguatoxins has hampered the development of a reliable and specific immunoassay for detecting these toxins in contaminated fish. Monoclonal antibodies (mAbs) specific against both ends of ciguatoxin CTX3C were prepared by immunization of mice with protein(More)
A functional hetero-oligomeric protein was, for the first time, displayed on the yeast cell surface. A hetero-oligomeric Fab fragment of the catalytic antibody 6D9 can hydrolyze a non-bioactive chloramphenicol monoester derivative to produce chloramphenicol. The gene encoding the light chain of the Fab fragment of 6D9 was expressed with the tandemly-linked(More)
BACKGROUND Small organic molecules coupled to a carrier protein elicit an antibody response on immunisation. The diversity of this response has been found to be very narrow in several cases. Some antibodies also catalyse chemical reactions. Such catalytic antibodies are usually identified among those that bind tightly to an analogue of the transition state(More)
Every year, more than 50,000 people in subtropical and tropical regions suffer from ciguatera seafood poisoning. The extremely low level of the causative neurotoxins (ciguatoxins) in fish has hampered the preparation of antibodies for detection of the toxins. In this study, we produced a monoclonal antibody (8H4) against the right end of ciguatoxin CTX1B(More)
For high-throughput screening of protein-protein interactions, we have developed a novel yeast screening system using Bimolecular fluorescence complementation (BiFC). Two yeast plasmids, in which genes of heterodimerized peptides LZA and LZB were each fused with those of non-fluorescent half fragments of Kusabira-Green mutant (mKG2), were transformed into(More)
Ciguatoxins (CTXs) are a family of toxins that contaminate a variety of fish and cause ciguatera seafood poisoning. The limited availability of CTXs from natural sources has hampered preparation of antibodies and, thus, the development of immunoassays for these toxins. In the current studies, we utilized synthetic fragments as haptens to prepare antibodies(More)
To address how proteins recognize polyether toxin compounds, we focused on the interaction between the ABC ring compound of ciguatoxin 3C and its specific antibody, 1C49. Surface plasmon resonance analyses indicated that Escherichia coli-expressed variable domain fragments (Fv) of 1C49 had the high affinity constants and slow dissociation constants typical(More)
Monoclonal antibodies (mAbs), 4H2 and 6H7, were prepared previously using a protein conjugate of a 1:1 epimeric mixture of the synthetic ABC-ring fragments of ciguatoxin (CTX), 3 and 4. Here, the interactions of these mAbs with the fragments of CTX and CTX3C, 3 and 5, were investigated by surface plasmon resonance (SPR) spectroscopy in an attempt to clarify(More)
Ciguatera fish poisoning (CFP) is a form of food poisoning caused by the consumption of fish that have accumulated a type of sodium channel activator toxin called ciguatoxins (CTXs), which are produced by dinoflagellates of the genus Gambierdiscus through the food chain. CFP affects more than 50000 people each year. The extremely low level of CTXs in(More)
Ciguatoxins are a family of marine toxins composed of transfused polycyclic ethers. It has not yet been clarified at the atomic level on the pathogenic mechanism of these toxins or the interaction between a polycyclic ether compounds and a protein. Using the crystal structures of anti-ciguatoxin antibody 10C9 Fab in ligand-free form and in complexes with(More)