Kiwamu Yamagishi
Fukuoka University
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Featured researches published by Kiwamu Yamagishi.
Bioorganic & Medicinal Chemistry Letters | 1996
Seiichiro Ogawa; Makoto Ashiura; Chikara Uchida; Shinsuke Watanabe; Chihiro Yamazaki; Kiwamu Yamagishi; Jin-ichi Inokuchi
Six homologous derivatives (N-butyl3a, hexyl 3b, octyl 3c, decyl 3d, tetradecyl 3e and stearyl 3f) of β-valienamine were synthesized. All have been shown to be potent and specific inhibitors of β-glucocerebrosidase, and to have no potency against glucosylceramide synthase (mouse liver microsomes). Among them, the N-octyl derivative possesses the strongest activity (IC50 3 × 10−8 M), being almost 10-fold more potent compared to the unsaturated 5a-carba-glucosylceramide 1. Compounds 3b and 3c are also moderate inhibitors of α-glucosidase (Bakers yeast).
Bioorganic & Medicinal Chemistry | 1998
Tsuyoshi Miura; Tetsuya Kajimoto; Masayuki Jimbo; Kiwamu Yamagishi; Jin-Chi Inokuchi; Chi-Huey Wong
This paper describes the new synthesis and evaluation of some morpholino- and pyrrolidinosphingolipids and mimics as inhibitors of glucosylceramide synthase. It was found that the pyrrolidino derivatives are generally more active than the morpholino derivatives and the best one was shown to be a nanomolar inhibitor.
Journal of Biological Chemistry | 2010
Nobuo Sugiura; Yuichi Baba; Yoshirou Kawaguchi; Toru Iwatani; Kiyoshi Suzuki; Takahiro Kusakabe; Kiwamu Yamagishi; Koji Kimata; Yoshimitsu Kakuta; Hideto Watanabe
Heparan sulfate is a ubiquitous glycosaminoglycan in the extracellular matrix of most animals. It interacts with various molecules and exhibits important biological functions. K5 antigen produced by Escherichia coli strain K5 is a linear polysaccharide N-acetylheparosan consisting of GlcUA β1–4 and GlcNAc α1–4 repeating disaccharide, which forms the backbone of heparan sulfate. Region 2, located in the center of the K5-specific gene cluster, encodes four proteins, KfiA, KfiB, KfiC, and KfiD, for the biosynthesis of the K5 polysaccharide. Here, we expressed and purified the recombinant KfiA and KfiC proteins and then characterized these enzymes. Whereas the recombinant KfiC alone exhibited no GlcUA transferase activity, it did exhibit GlcUA transferase and polymerization activities in the presence of KfiA. In contrast, KfiA had GlcNAc transferase activity itself, which was unaffected by the presence of KfiC. The GlcNAc and GlcUA transferase activities were analyzed with various truncated and point mutants of KfiA and KfiC. The point mutants replacing aspartic acid of a DXD motif and lysine and glutamic acid of an ionic amino acid cluster, and the truncated mutants deleting the C-terminal and N-terminal sites, revealed the essential regions for GlcNAc and GlcUA transferase activity of KfiC and KfiA, respectively. The interaction of KfiC with KfiA is necessary for the GlcUA transferase activity of KfiC but not for the enzyme activity of KfiA. Together, these results indicate that the complex of KfiA and KfiC has polymerase activity to synthesize N-acetylheparosan, providing a useful tool toward bioengineering of defined heparan sulfate chains.
European Journal of Pharmacology | 2003
Kiwamu Yamagishi; Kenichi Mishima; Yusuke Ohgami; Katsunori Iwasaki; Masayuki Jimbo; Hiroyuki Masuda; Yasuyuki Igarashi; Jin-ichi Inokuchi; Michihiro Fujiwara
A synthetic ceramide analog, L-threo-1-phenyl-2-decanoylamino-3-morpholino-1-propanol (L-PDMP) upregulates ganglioside biosynthesis in several cell lines. In cultured cortical neurons, neurotrophic effects of L-PDMP on neurite outgrowth and synaptic activity were demonstrated. In addition, it was found that L-PDMP could ameliorate the spatial cognition deficit in rats with ischemia. To elucidate this effect, we evaluated the effect of L-PDMP on brain ganglioside biosynthesis and its therapeutic efficacy against spatial cognition deficit in rats made ischemic. Rats were trained for 2 weeks, using an 8-arm radial maze task, and then forebrain ischemia was induced. L-PDMP was injected i.p. at 40 mg/kg twice a day starting from day 1 or 3 after ischemia induction for 6 or 4 days, respectively. The first study showed significantly reduced spatial cognition deficit at 12 h after the final drug administration, and L-PDMP tended to attenuate apoptosis in hippocampal CA1. To examine the effect of L-PDMP on brain ganglioside biosynthesis, N-[3H]acetyl-D-mannosamine was infused into the lateral ventricle via an injection cannula at 12 h after the final drug administration. After 4 h, the brain gangliosides were purified and analyzed. Upregulation of ganglioside biosynthesis by L-PDMP was observed on days 3 and 5 after ischemia. These results are an indication that L-PDMP may ameliorate spatial cognition deficit by upregulating ganglioside biosynthesis in ischemic brain.
Bioorganic & Medicinal Chemistry Letters | 1997
Seiichiro Ogawa; Tamami Mito; Eiichi Taiji; Masayuki Jimbo; Kiwamu Yamagishi; Jin-ichi Inokuchi
Abstract All stereoisomers with regard to C-1 and 2 of 1-phenyl-2-decanoylamino-3-morpholino-1-propanol (PDMP) analogue containing unsaturated (β-valienamine) and saturated 5a-carba-β- d -glucopyranosylamine (β-validamine) residues in place of morpholine moiety were synthesized. Although PDMP is a potent and specific glucosylceramide synthase inhibitor, the former valienamine analogues (4a-d) have been shown to be strong glucocerebrosidase inhibitors ( IC 50 3–7 ∗x 10 −7 M). The latter validamine analogues (5a-d) were also moderate glucocerebrosidase inhibitors ( IC 50 5–20 ∗x 10 −6 M). A series of compounds synthesized lacked an inhibitory potency against the glucosyltransferase at all. Whereas the analogue 6a composed of epimeric α-valienamine residue did not possess any potency against both enzymes.
Glycobiology | 2015
Hideo Mochizuki; Kiwamu Yamagishi; Kiyoshi Suzuki; Yeong Shik Kim; Koji Kimata
Iduronic acid (IdoA) is a critical component of heparan sulfate in its interaction with functional proteins. Heparosan-N-sulfate-glucuronate 5-epimerase (HNSG-5epi) converts d-glucuronic acid (GlcA) residues in N-sulfated heparosan (NS-heparosan), as an intermediate in heparan sulfate biosynthesis, to IdoA. In the present study, the authors discovered a different 5-epimerase, designated HG-5epi (heparosan-glucuronate 5-epimerase), that is involved in acharan sulfate biosynthesis and possesses novel substrate specificity. A candidate cDNA of HG-5epi was cloned from the cDNA library of Achatina fulica. The cloned cDNA contained a whole coding region that predicts a type II transmembrane protein composed of 601 amino acid residues. The amino acid sequence of HG-5epi is homologous to that of HNSG-5epi. Recombinant HG-5epi was expressed in insect cells and its enzymatic properties characterized. As expected, HG-5epi epimerizes GlcA residues in heparosan, but not in NS-heparosan. Conversion of IdoA to GlcA was also catalyzed by HG-5epi when completely desulfated N-acetylated heparin was used as the substrate, indicating a reversible reaction mechanism. At equilibrium of the epimerization, the proportion of IdoA in the reaction product reached up to 30% of total hexuronic acid. To our knowledge, this is the first report to describe an enzyme that catalyzes the epimerization of non-sulfated heparosan. This new enzyme may be applied to the study of synthetic heparan sulfate-related polysaccharides having certain biological and pharmacological activities. In addition, a new method using anion-exchange HPLC connected to a post-column fluorescent labeling system was developed for analyzing hexuronic acid isomers.
Neuroscience Research | 1997
Akihiro Mizutani; Yoichiro Kuroda; Kazuyo Muramoto; Kazuo Kobayashi; Kiwamu Yamagishi; Jin-ichi Inokuchi
345 POSTSYNAPTIC LOCALIZATION OF SYNAPTOPHOSCAN (MAPlB) IN THE CERE BRAL CORTEX Department of Anatomy & Embryology, Tokyo Metropolitan Institute for Neuroscience, 2-6 Musashidai, Fuchu-shi, Tokyo’, Department of Molecular & Cellular Neurobiology, Tokyo Metropolitan Institute for Neuroscience, 2-6 Musashidai, Fuchu-shi, Tokyo 2, School of Agricultural Science, Nagoya University, Furou-cho, Chikusa-ku, Nagoya3
Biochemical and Biophysical Research Communications | 1997
Jin-ichi Inokuchi; Akihiro Mizutani; Masayuki Jimbo; Seigou Usuki; Kiwamu Yamagishi; Hideo Mochizuki; Kazuyo Muramoto; Kazuo Kobayashi; Yoichiro Kuroda; Katsunori Iwasaki; Yusuke Ohgami; Michihiro Fujiwara
Biochemical and Biophysical Research Communications | 1996
Akihiro Mizutani; Yoichiro Kuroda; Kazuyo Muramoto; Kazuo Kobayashi; Kiwamu Yamagishi; Jin-ichi Inokuchi
Journal of Biological Chemistry | 2003
Kiwamu Yamagishi; Kiyoshi Suzuki; Kyoko Imai; Hideo Mochizuki; Kiyoshi Morikawa; Mamoru Kyogashima; Koji Kimata; Hideto Watanabe
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National Institute of Advanced Industrial Science and Technology
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