Kohki Ishikawa

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The crystal structure of a microbial transglutaminase from Streptoverticillium mobaraense has been determined at 2.4 A resolution. The protein folds into a plate-like shape, and has one deep cleft at the edge of the molecule. Its overall structure is completely different from that of the factor XIII-like transglutaminase, which possesses a cysteine(More)
Incorporation of inter- or intramolecular covalent cross-links into food proteins with microbial transglutaminase (MTG) improves the physical and textural properties of many food proteins, such as tofu, boiled fish paste, and sausage. By using nuclear magnetic resonance, we have shown that the residues exhibiting relatively high flexibility in MTG are(More)
The crystal structure of Bifidobacterium longum phosphoketolase, a thiamine diphosphate (TPP) dependent enzyme, has been determined at 2.2A resolution. The enzyme is a dimer with the active sites located at the interface between the two identical subunits with molecular mass of 92.5 kDa. The bound TPP is almost completely shielded from solvent except for(More)
Brazzein is the smallest sweet-tasting protein and was isolated from the wild African plant Pentadiplandra brazzeana. The brazzein molecule consists of 54 amino-acid residues and four disulfide bonds. Here, the first crystal structure of brazzein is reported at 1.8 Å resolution and is compared with previously reported solution structures. Despite the(More)
Escherichia blattae acid phosphatase/phosphotransferase (EB-AP/PTase) exhibits C-5'-position selective pyrophosphate-nucleoside phosphotransferase activity in addition to its intrinsic phosphatase. Improvement of its phosphotransferase activity was investigated by sequential site-directed mutagenesis. By comparing the primary structures of higher(More)
Escherichia blattae non-specific acid phosphatase (EB-NSAP) possesses a pyrophosphate-nucleoside phosphotransferase activity, which is C-5'-position selective. Current mutational and structural data were used to generate a mutant EB-NSAP for a potential industrial application as an effective and economical protein catalyst in synthesizing nucleotides from(More)
Atsushi Manabe, Setsuya Kawabata, Youhei Morita, Takashi Sasaki, Hiroyuki Sato, Yoshiyuki Watase and Shigeo Yashiro High Energy Accelerator Research Organization,KEK, Tsukuba,Japan Tetsuro Mashimo,Hiroshi Matsumoto, Hiroshi Sakamoto,Junichi Tanaka, Ikuo Ueda International Center for Elementary Particle Physics University of Tokyo (ICEPP, Tokyo, Japan) Kohki(More)
In this study, we developed an assignment-free approach for rapid identification of ligand-binding sites in target proteins by using NMR. With a sophisticated cell-free stable isotope-labeling procedure that introduces (15)N- or (13)C-labels to specific atoms of target proteins, this approach requires only a single series of ligand titrations with labeled(More)
An inhibitor of factor Xa (fXa), the m-substituted benzamidine AXC1578 (1a), was structurally modified with the aim of increasing its potency. In particular, pyruvic acid and propionic acid substituents were incorporated into the P1 benzamidine moiety to introduce a favorable interaction with the oxy-anion hole in the catalytic triad region of fXa. This(More)
X-ray crystal structural determination of FABP4 in complex with four inhibitors revealed the complex binding modes, and the resulting observations led to improvement of the inhibitory potency of FABP4 inhibitors. However, the detailed structure-activity relationship (SAR) could not be explained from these structural observations. For a more detailed(More)
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