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61.
Kentaro Ito Makoto Yamaguchi Teruyuki Noma Taketo Yamaji Hiroyuki Itoh Munehiro Oda 《Bioscience, biotechnology, and biochemistry》2016,80(8):1587-1593
We evaluated the effect of whey protein hydrolysates (WPH) on the water absorption rate in the small intestine using a rat small intestine perfusion model. The rate was significantly higher with 5 g/L WPH than with 5 g/L soy protein hydrolysates or physiological saline (p?0.05). WPH dose-dependently increased the water absorption rate in the range of 1.25–10.0 g/L. WPH showed a significantly higher rate than an amino acid mixture whose composition was equal to that of WPH (p?0.05). The addition of 4-aminomethylbenzoic acid, an inhibitor of PepT1, significantly suppressed WPH’s enhancement of water absorption (p?0.05). The rate of water absorption was significantly correlated with that of peptides/amino acids absorption in WPH (r?=?0.82, p?0.01). These data suggest that WPH have a high water absorption-promoting effect, to which PepT1 contributes. 相似文献
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Kamimura M Saito H Niwa R Niimi T Toyoda K Ueno C Kanamori Y Shimura S Kiuchi M 《The Journal of biological chemistry》2012,287(20):16488-16498
Steroid hormones ecdysteroids regulate varieties of developmental processes in insects. Although the ecdysteroid titer can be increased experimentally with ease, its artificial reduction, although desirable, is very difficult to achieve. Here we characterized the ecdysteroid-inactivating enzyme ecdysteroid-22-oxidase (E22O) from the entomopathogenic fungus Nomuraea rileyi and used it to develop methods for reducing ecdysteroid titer and thereby controlling insect development. K(m) and K(cat) values of the purified E22O for oxidizing ecdysone were 4.4 μM and 8.4/s, respectively, indicating that E22O can inactivate ecdysone more efficiently than other ecdysteroid inactivating enzymes characterized so far. The cloned E22O cDNA encoded a FAD-dependent oxidoreductase. Injection of recombinant E22O into the silkworm Bombyx mori interfered with larval molting and metamorphosis. In the hemolymph of E22O-injected pupae, the titer of hormonally active 20-hydroxyecdysone decreased and concomitantly large amounts of inactive 22-dehydroecdysteroids accumulated. E22O injection also prevented molting of various other insects. In the larvae of the crambid moth Haritalodes basipunctalis, E22O injection induced a diapause-like developmental arrest, which, as in normal diapause, was broken by chilling. Transient expression of the E22O gene by in vivo lipofection effectively decreased the 20-hydroxyecdysone titer and blocked molting in B. mori. Transgenic expression of E22O in Drosophila melanogaster caused embryonic morphological defects, phenotypes of which were very similar to those of the ecdysteroid synthesis deficient mutants. Thus, as the first available simple but versatile tool for reducing the internal ecdysteroid titer, E22O could find use in controlling a broad range of ecdysteroid-associated developmental and physiological phenomena. 相似文献
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65.
Yamasaki T Deguchi M Fujimoto T Masumura T Uno T Kanamaru K Yamagata H 《Bioscience, biotechnology, and biochemistry》2006,70(5):1200-1209
The complete nucleotide sequences of the cDNA and its gene that encode a bifunctional alpha-amylase/subtilisin inhibitor of rice (Oryza sativa L.) (RASI) were analyzed. RASI cDNA (939 bp) encoded a 200-residue polypeptide with a molecular mass of 21,417 Da, including a signal peptide of 22 amino acids. Sequence comparison and phylogenetic analysis showed that RASI is closely related to alpha-amylase/subtilisin inhibitors from barley and wheat. RASI was found to be expressed only in seeds, suggesting that it has a seed-specific function. A coding region of RASI cDNA without the signal peptide was introduced into Escherichia coli and was expressed as a His-tagged protein. Recombinant RASI was purified to homogeneity in a single step by Ni-chelating affinity column chromatography and characterized to elucidate the target enzyme. The recombinant inhibitor had strong inhibitory activity toward subtilisin, with an equimolar relationship, comparable with that of native RASI, and weak inhibitory activity toward some microbial alpha-amylases, but not toward animal or insect alpha-amylases. These results suggest that RASI might function in the defense of the seed against microorganisms. 相似文献
66.
Morihiro Mitsuya Kenji Kamata Makoto Bamba Hitomi Watanabe Yasuhiro Sasaki Kaori Sasaki Sumika Ohyama Hideka Hosaka Yasufumi Nagata Jun-ichi Eiki Teruyuki Nishimura 《Bioorganic & medicinal chemistry letters》2009,19(10):2718-2721
A novel class of 3,6-disubstituted 2-pyridinecarboxamide derivatives was designed based on X-ray analysis of the 2-aminobenzamide lead class. Subsequent chemical modification led to the discovery of potent GK activators which eliminate potential toxicity concerns associated with an aniline group of the lead structure. Compound 7 demonstrated glucose lowering effect in a rat OGTT model. 相似文献
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Tomoharu Iino Yasuhiro Sasaki Makoto Bamba Morihiro Mitsuya Akio Ohno Kenji Kamata Hideka Hosaka Hiroko Maruki Mayumi Futamura Riki Yoshimoto Sumika Ohyama Kaori Sasaki Masato Chiba Norikazu Ohtake Yasufumi Nagata Jun-ichi Eiki Teruyuki Nishimura 《Bioorganic & medicinal chemistry letters》2009,19(19):5531-5538
We describe design, syntheses and structure–activity relationships of a novel class of 4,6-disubstituted quinazoline glucokinase activators. Prototype quinazoline leads (4 and 5) were designed based on the X-ray analyses of the previous 2-aminobenzamide lead classes. Modifications of the quinazoline leads led to the identification of a potent GK activator (21d). 相似文献
69.
70.
Tomoharu Iino Noriaki Hashimoto Takuro Hasegawa Masato Chiba Jun-ichi Eiki Teruyuki Nishimura 《Bioorganic & medicinal chemistry letters》2010,20(5):1619-1622
Glucokinase activators (GKAs) are currently under investigation as potential antidiabetic agents by many pharmaceutical companies. Most of GKAs reported previously possess N-aminothiazol-2-yl amide moiety in their structures because the aminothiazole moiety interacts with glucokinase (GK) and shows strong GK activation. During the development of N-aminothiazol-2-yl amide derivatives, we identified a bioactivation and metabolic liability of 2-aminothizole substructure of GKA 3 by assessing covalent binding, metabolites in liver microsomes and glutathione (GSH) trap assay. 相似文献