研究者データベース

研究者情報

マスター

アカウント(マスター)

  • 氏名

    野村 尚生(ノムラ タカオ), ノムラ タカオ

所属(マスター)

  • 薬学研究院 創薬科学研究教育センター

所属(マスター)

  • 薬学研究院 創薬科学研究教育センター

独自項目

syllabus

  • 2020, 物理化学Ⅱ, Physical Chemistry II, 学士課程, 薬学部, 熱力学、平衡、物質の状態、溶液化学、電気化学

researchmap

プロフィール情報

学位

  • 博士(理学)(北海道大学)

プロフィール情報

  • 野村, ノムラ
  • 尚生, タカオ
  • ID各種

    201501057208028208

業績リスト

研究キーワード

  • ペプチド・タンパク質化学   創薬スクリーニング   創薬科学   

研究分野

  • ライフサイエンス / 薬系化学、創薬科学

経歴

  • 2013年09月 - 現在 北海道大学大学院薬学研究院 特任助教
  • 2011年04月 - 2013年08月 慶應義塾大学理工学部化学科 助教(有期)
  • 2010年09月 - 2011年03月 北海道大学 電子科学研究所 博士研究員

学歴

  • 2007年04月 - 2010年03月   日本学術振興会 特別研究員(DC1)
  • 2006年10月 - 2009年09月   北海道大学   大学院理学院   化学専攻 (博士(理学))
  • 2005年04月 - 2006年09月   北海道大学   大学院理学研究院   化学専攻 博士前期課程
  • 2001年04月 - 2005年03月   北海道大学   理学部   化学科

論文

  • Hirofumi Ohashi, Koichi Watashi, Wakana Saso, Kaho Shionoya, Shoya Iwanami, Takatsugu Hirokawa, Tsuyoshi Shirai, Shigehiko Kanaya, Yusuke Ito, Kwang Su Kim, Takao Nomura, Tateki Suzuki, Kazane Nishioka, Shuji Ando, Keisuke Ejima, Yoshiki Koizumi, Tomohiro Tanaka, Shin Aoki, Kouji Kuramochi, Tadaki Suzuki, Takao Hashiguchi, Katsumi Maenaka, Tetsuro Matano, Masamichi Muramatsu, Masayuki Saijo, Kazuyuki Aihara, Shingo Iwami, Makoto Takeda, Jane A McKeating, Takaji Wakita
    iScience 24 4 102367 - 102367 2021年04月23日 
    Antiviral treatments targeting the coronavirus disease 2019 are urgently required. We screened a panel of already approved drugs in a cell culture model of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and identified two new agents having higher antiviral potentials than the drug candidates such as remdesivir and chroloquine in VeroE6/TMPRSS2 cells: the anti-inflammatory drug cepharanthine and human immunodeficiency virus protease inhibitor nelfinavir. Cepharanthine inhibited SARS-CoV-2 entry through the blocking of viral binding to target cells, while nelfinavir suppressed viral replication partly by protease inhibition. Consistent with their different modes of action, synergistic effect of this combined treatment to limit SARS-CoV-2 proliferation was highlighted. Mathematical modeling in vitro antiviral activity coupled with the calculated total drug concentrations in the lung predicts that nelfinavir will shorten the period until viral clearance by 4.9 days and the combining cepharanthine/nelfinavir enhanced their predicted efficacy. These results warrant further evaluation of the potential anti-SARS-CoV-2 activity of cepharanthine and nelfinavir.
  • Natsumi Nakagawa, Shuya Sakaguchi, Takao Nomura, Rui Kamada, James G Omichinski, Kazuyasu Sakaguchi
    Biochemical and biophysical research communications 521 3 681 - 686 2020年01月15日 [査読有り][通常論文]
     
    The p53 protein plays a number of roles in protecting organisms from different genotoxic stresses and this includes DNA damage induced by acetaldehyde, a metabolite of alcohol. Since the common tree shrew ingests high levels of alcohol as part of its normal diet, this suggests that its p53 protein may possess unique properties. Using a combination of biophysical and modeling studies, we demonstrate that the tetramerization domain of the tree shrew p53 protein is considerably more stable than the corresponding domain from humans despite sharing almost 90% sequence identity. Based on modeling and mutagenesis studies, we determine that a glutamine to methionine substitution at position 354 plays a key role in this difference. Given the link between stability of the p53 tetramerization domain and its transcriptional activity, the results suggest that this enhanced stability could lead to important consequences at p53-regulated genes in the tree shrew.
  • Wataru Kakuguchi, Takao Nomura, Tetsuya Kitamura, Satoko Otsuguro, Kazuhiro Matsushita, Masahiro Sakaitani, Katsumi Maenaka, Kanchu Tei
    Cancer medicine 7 12 6269 - 6280 2018年12月 [査読有り][通常論文]
     
    AU-rich elements (ARE) exist in the 3'-untranslated regions of the mRNA transcribed from cell growth-related genes such as proto-oncogenes, cyclin-related genes, and growth factors. HuR binds and stabilizes ARE-mRNA. HuR is expressed abundantly in cancer cells and related malignant phenotypes. HuR knockdown attenuates the malignant phenotype of oral cancer cells. In this study, we screened 1570 compounds in the approved drug library by differential scanning fluorimetry (DSF) to discover a HuR-targeted compound. Firstly, 55 compounds were selected by DSF. Then, 8 compounds that showed a shift in the melting temperature value in a concentration-dependent manner were selected by DSF. Of them, suramin, an anti-trypanosomal drug, binds to HuR, exhibiting fast-on and fast-off kinetic behavior on surface plasmon resonance (SPR). We confirmed that suramin significantly decreased mRNA and protein expression of cyclin A2 and cyclin B1. The cyclin A2 and cyclin B1 mRNAs were destabilized by suramin. Furthermore, the motile and invasive activities of a tongue carcinoma cell line treated with suramin were markedly lower than those of control cells. The above findings suggest that suramin binds to HuR and inhibits its function. We also showed that the anticancer effects of suramin were caused by the inhibition of HuR function, indicating its potential as a novel therapeutic agent in the treatment of oral cancer. Our results suggest that suramin, via its different mechanism, may effectively suppress progressive oral cancer that cannot be controlled using other anticancer agents.
  • Tokuda Eiichi, Nomura Takao, Ohara Shinji, Watanabe Seiji, Yamanaka Koji, Morisaki Yuta, Misawa Hidemi, Furukawa Yoshiaki
    Biochimica et Biophysica Acta - Molecular Basis of Disease 1864 6 2119 - 2130 2018年06月01日 [査読有り][通常論文]
     
    <p>Dominant mutations in the gene encoding copper and zinc-binding superoxide dismutase (SOD1) cause amyotrophic lateral sclerosis (ALS). Abnormal accumulation of misfolded SOD1 proteins in spinal motoneurons is a major pathological hallmark in SOD1-related ALS. Dissociation of copper and/or zinc ions from SOD1 has been shown to trigger the protein aggregation/oligomerization in vitro, but the pathological contribution of such metal dissociation to the SOD1 misfolding still remains obscure. Here, we tested the relevance of the metal-deficient SOD1 in the misfolding in vivo by developing a novel antibody (anti-apoSOD), which exclusively recognized mutant SOD1 deficient in metal ions at its copper-binding site. Notably, anti-apoSOD-reactive species were detected specifically in the spinal cords of the ALS model mice only at their early pre-symptomatic stages but not at the end stage of the disease. The cerebrospinal fluid as well as the spinal cord homogenate of one SOD1-ALS patient also contained the anti-apoSOD-reactive species. Our results thus suggest that metal-deficiency in mutant SOD1 at its copper-binding site is one of the earliest pathological features in SOD1-ALS.</p>
  • Tokuda E, Nomura T, Ohara S, Watanabe S, Yamanaka K, Morisaki Y, Misawa H, Furukawa Y
    Biochimica et biophysica acta 1864 6 Pt A 2119 - 2130 2018年06月 [査読有り][通常論文]
  • Yaguchi H, Yabe I, Takahashi H, Watanabe M, Nomura T, Kano T, Matsumoto M, Nakayama KI, Watanabe M, Hatakeyama S
    Biochemical and biophysical research communications 494 1-2 234 - 241 2017年12月 [査読有り][通常論文]
  • Furukawa A, Kakita K, Yamada T, Ishizuka M, Sakamoto J, Hatori N, Maeda N, Ohsaka F, Saitoh T, Nomura T, Kuroki K, Nambu H, Arase H, Matsunaga S, Anada M, Ose T, Hashimoto S, Maenaka K
    The Journal of biological chemistry 292 51 21128 - 21136 2017年12月 [査読有り][通常論文]
     
    Before entering host cells, herpes simplex virus-1 uses its envelope glycoprotein B to bind paired immunoglobulin-like type 2 receptor alpha (PILR alpha) on immune cells. PILR alpha belongs to the Siglec (sialic acid (SA)-binding immunoglobulin-like lectin)- like family, members of which bind SA. PILR alpha is the only Siglec member to recognize not only the sialylated O-linked sugar T antigen (sTn) but also its attached peptide region. We previously determined the crystal structure of PILR alpha complexed with the sTn-linked glycopeptide of glycoprotein B, revealing the simultaneous recognition of sTn and peptide by the receptor. However, the contribution of each glycopeptide component to PILR alpha binding was largely unclear. Here, we chemically synthesized glycopeptide derivatives and determined the thermodynamic parameters of their interaction with PILR alpha. We show that glycopeptides with different sugar units linking SA and peptides (i.e. "GlcNAc-type" and "deoxy-GlcNAc-type" glycopeptides) have lower affinity and more enthalpy-driven binding than the wild type (i.e. GalNAc-type glycopeptide). The crystal structures of PILR alpha complexed with these glycopeptides highlighted the importance of stereochemical positioning of the O4 atom of the sugar moiety. These results provide insights both for understanding the unique O-glycosylated peptide recognition by the PILR alpha and for the rational design of herpes simplex virus-1 entry inhibitors.
  • Takanori Matsumaru, Makoto Inai, Kana Ishigami, Toshiki Iwamatsu, Hiroshi Maita, Satoko Otsuguro, Takao Nomura, Akira Matsuda, Satoshi Ichikawa, Masahiro Sakaitani, Satoshi Shuto, Katsumi Maenaka, Toshiyuki Kan
    BIOORGANIC & MEDICINAL CHEMISTRY LETTERS 27 10 2144 - 2147 2017年05月 [査読有り][通常論文]
     
    We accomplished divergent synthesis of potent kinase inhibitor BAY 61-3606 (1) and 27 derivatives via conjugation of imidazo[1,2-c]pyrimidine and indole ring compounds with aromatic (including pyridine) derivatives by means of palladium-catalyzed cross-coupling reaction. Spleen tyrosine kinase (Syk) and germinal center kinase (Gck, MAP4K2) inhibition assays showed that some of the synthesized compounds were selective Gck inhibitors. (C) 2017 Elsevier Ltd. All rights reserved.
  • Eiichi Tokuda, Itsuki Anzai, Takao Nomura, Keisuke Toichi, Masahiko Watanabe, Shinji Ohara, Seiji Watanabe, Koji Yamanaka, Yuta Morisaki, Hidemi Misawa, Yoshiaki Furukawa
    MOLECULAR NEURODEGENERATION 12 1 2  2017年01月 [査読有り][通常論文]
     
    Background: Dominant mutations in Cu/Zn-superoxide dismutase (SOD1) gene cause a familial form of amyotrophic lateral sclerosis (SOD1-ALS) with accumulation of misfolded SOD1 proteins as intracellular inclusions in spinal motor neurons. Oligomerization of SOD1 via abnormal disulfide crosslinks has been proposed as one of the misfolding pathways occurring in mutant SOD1; however, the pathological relevance of such oligomerization in the SOD1-ALS cases still remains obscure. Methods: We prepared antibodies exclusively recognizing the SOD1 oligomers cross-linked via disulfide bonds in vitro. By using those antibodies, immunohistochemical examination and ELISA were mainly performed on the tissue samples of transgenic mice expressing mutant SOD1 proteins and also of human SOD1-ALS cases. Results: We showed the recognition specificity of our antibodies exclusively toward the disulfide-crosslinked SOD1 oligomers by ELISA using various forms of purified SOD1 proteins in conformationally distinct states in vitro. Furthermore, the epitope of those antibodies was buried and inaccessible in the natively folded structure of SOD1. The antibodies were then found to specifically detect the pathological SOD1 species in the spinal motor neurons of the SOD1-ALS patients as well as the transgenic model mice. Conclusions: Our findings here suggest that the SOD1 oligomerization through the disulfide-crosslinking associates with exposure of the SOD1 structural interior and is a pathological process occurring in the SOD1-ALS cases.
  • Rui Kamada, Yu Toguchi, Takao Nomura, Toshiaki Imagawa, Kazuyasu Sakaguchi
    BIOPOLYMERS 106 4 598 - 612 2016年07月 [査読有り][通常論文]
     
    Tetramer formation of p53 is essential for its tumor suppressor function. p53 not only acts as a tumor suppressor protein by inducing cell cycle arrest and apoptosis in response to genotoxic stress, but it also regulates other cellular processes, including autophagy, stem cell self-renewal, and reprogramming of differentiated cells into stem cells, immune system, and metastasis. More than 50% of human tumors have TP53 gene mutations, and most of them are missense mutations that presumably reduce tumor suppressor activity of p53. This review focuses on the role of the tetramerization (oligomerization), which is modulated by the protein concentration of p53, posttranslational modifications, and/or interactions with its binding proteins, in regulating the tumor suppressor function of p53. Functional control of p53 by stabilizing or inhibiting oligomer formation and its bio-applications are also discussed. (C) 2015 Wiley Periodicals, Inc.
  • Yoshiaki Furukawa, Itsuki Anzai, Shuji Akiyama, Mizue Imai, Fatima Joy C. Cruz, Tomohide Saio, Kenichi Nagasawa, Takao Nomura, Koichiro Ishimori
    JOURNAL OF BIOLOGICAL CHEMISTRY 291 8 4144 - 4155 2016年02月 [査読有り][通常論文]
     
    Misfolding of Cu,Zn-superoxide dismutase (SOD1) is a pathological change in the familial form of amyotrophic lateral sclerosis caused by mutations in the SOD1 gene. SOD1 is an enzyme that matures through the binding of copper and zinc ions and the formation of an intramolecular disulfide bond. Pathogenic mutations are proposed to retard the post-translational maturation, decrease the structural stability, and hence trigger the misfolding of SOD1 proteins. Despite this, a misfolded and potentially pathogenic conformation of immature SOD1 remains obscure. Here, we show significant and distinct conformational changes of apoSOD1 that occur only upon reduction of the intramolecular disulfide bond in solution. In particular, loop regions in SOD1 lose their restraint and become significantly disordered upon dissociation of metal ions and reduction of the disulfide bond. Such drastic changes in the solution structure of SOD1 may trigger misfolding and fibrillar aggregation observed as pathological changes in the familial form of amyotrophic lateral sclerosis.
  • Takao Nomura, Shoji Watanabe, Kumi Kaneko, Koji Yamanaka, Nobuyuki Nukina, Yoshiaki Furukawa
    JOURNAL OF BIOLOGICAL CHEMISTRY 289 2 1192 - 1202 2014年01月 [査読有り][通常論文]
     
    Dominant mutations in FUS/TLS cause a familial form of amyotrophic lateral sclerosis (fALS), where abnormal accumulation of mutant FUS proteins in cytoplasm has been observed as a major pathological change. Many of pathogenic mutations have been shown to deteriorate the nuclear localization signal in FUS and thereby facilitate cytoplasmic mislocalization of mutant proteins. Several other mutations, however, exhibit no effects on the nuclear localization of FUS in cultured cells, and their roles in the pathomechanism of fALS remain obscure. Here, we show that a pathogenic mutation, G156E, significantly increases the propensities for aggregation of FUS in vitro and in vivo. Spontaneous in vitro formation of amyloid-like fibrillar aggregates was observed in mutant but not wild-type FUS, and notably, those fibrils functioned as efficient seeds to trigger the aggregation of wild-type protein. In addition, the G156E mutation did not disturb the nuclear localization of FUS but facilitated the formation of intranuclear inclusions in rat hippocampal neurons with significant cytotoxicity. We thus propose that intranuclear aggregation of FUS triggered by a subset of pathogenic mutations is an alternative pathomechanism of FUS-related fALS diseases.
  • Yasushi Mitomi, Takao Nomura, Masaru Kurosawa, Nobuyuki Nukina, Yoshiaki Furukawa
    JOURNAL OF BIOLOGICAL CHEMISTRY 287 41 34764 - 34775 2012年10月 [査読有り][通常論文]
     
    Aggregation of protein molecules is a pathological hallmark of many neurodegenerative diseases. Abnormal modifications have often been observed in the aggregated proteins, supporting the aggregation mechanism regulated by post-translational modifications on proteins. Modifications are in general assumed to occur in soluble proteins before aggregation, but actually it remains quite obscure when proteins are modified in the course of the aggregation. Here we focus upon aggregation of huntingtin (HTT), which causes a neurodegenerative disorder, Huntington disease, and we show that oxidation of a methionine residue in HTT occurs in vitro and also in vivo. Copper ions as well as added hydrogen peroxide are found to oxidize the methionine residue, but notably, this oxidative modification occurs only in the aggregated HTT but not in the soluble state. Furthermore, the methionine oxidation creates additional interactions among HTT aggregates and alters overall morphologies of the aggregates. We thus reveal that protein aggregates can be a target of oxidative modifications and propose that such a "post-aggregation" modification is a relevant factor to regulate properties of protein aggregates.
  • Takao Nomura, Rui Kamada, Issaku Ito, Koichi Sakamoto, Yoshiro Chuman, Koichiro Ishimori, Yasuyuki Shimohigashi, Kazuyasu Sakaguchi
    BIOPOLYMERS 95 6 410 - 419 2011年06月 [査読有り][通常論文]
     
    Stabilization of protein structures and protein protein interactions are critical in the engineering of industrially useful enzymes and in the design of pharmaceutically valuable ligands. Hydrophobic interactions involving phenylalanine residues play crucial roles in protein stability and protein-protein/peptide interactions. To establish an effective method to explore the hydrophobic environments of phenylalanine residues, we present a strategy that uses pentafluorophenylalanine (F(5)Phe) and cyclohexylalanine (Cha). In this study, substitution of F(5)Phe or Cha for three Phe residues at positions 328, 338, and 341 in the tetramerization domain of the tumor suppressor protein p53 was performed. These residues are located at the interfaces of p53 p53 interactions and are important in the stabilization of the tetrameric structure. The stability of the p53 tetrameric structure did not change significantly when F(5)Phe-containing peptides at positions Phe328 or Phe338 were used. In contrast, the substitution of Cha for Phe341 in the hydrophobic core enhanced the stability of the tetrameric structure with a T(m) value of similar to 100 degrees C. Phe328 and Phe338 interact with each other through pi-interactions, whereas Phe341 is buried in the surrounding alkyl side-chains of the hydrophobic core of the p53 tetramerization domain. Furthermore, high pressure-assisted denaturation analysis indicated improvement in the occupancy of the hydrophobic core. Considerable stabilization of the p53 tetramer was achieved by filling the identified cavity in the hydrophobic core of the p.5.3 tetramer. The results indicate the status of the Phe residues, indicating that the "pair substitution" of Cha and F(5)Phe is highly suitable for probing the environments of Phe residues. (C) 2011 Wiley Periodicals, Inc. Biopolymers 95: 410-419, 2011.
  • Rui Kamada, Takao Nomura, Carl W. Anderson, Kazuyasu Sakaguchi
    JOURNAL OF BIOLOGICAL CHEMISTRY 286 1 252 - 258 2011年01月 [査読有り][通常論文]
     
    The tumor suppressor p53, a 393-amino acid transcription factor, induces cell cycle arrest and apoptosis in response to genotoxic stress. Its inactivation via the mutation of its gene is a key step in tumor progression, and tetramer formation is critical for p53 post-translational modification and its ability to activate or repress the transcription of target genes vital in inhibiting tumor growth. About 50% of human tumors have TP53 gene mutations; most are missense ones that presumably lower the tumor suppressor activity of p53. In this study, we explored the effects of known tumor-derived missense mutations on the stability and oligomeric structure of p53; our comprehensive, quantitative analyses encompassed the tetramerization domain peptides representing 49 such substitutions in humans. Their effects on tetrameric structure were broad, and the stability of the mutant peptides varied widely (Delta T(m) = 4.8 similar to -46.8 degrees C). Because formation of a tetrameric structure is critical for protein-protein interactions, DNA binding, and the post-translational modification of p53, a small destabilization of the tetrameric structure could result in dysfunction of tumor suppressor activity. We suggest that the threshold for loss of tumor suppressor activity in terms of the disruption of the tetrameric structure of p53 could be extremely low. However, other properties of the tetramerization domain, such as electrostatic surface potential and its ability to bind partner proteins, also may be important.
  • Rui Kamada, Wataru Yoshino, Takao Nomura, Yoshiro Chuman, Toshiaki Imagawa, Takanori Suzuki, Kazuyasu Sakaguchi
    BIOORGANIC & MEDICINAL CHEMISTRY LETTERS 20 15 4412 - 4415 2010年08月 [査読有り][通常論文]
     
    Li-Fraumeni syndrome, a hereditary disorder characterized by familial clusters of early-onset multiple tumors, is caused by mutation of the TP53 gene, which encodes the p53 tumor suppressor protein. Mutation of Arg337 to histidine in the tetramerization domain of p53 is most frequently observed in Li-Fraumeni syndrome. This mutation is reported to destabilize the tetrameric structure of p53. We designed and synthesized calix[6] arene derivatives, which have six imidazole or pyrazole groups at the upper rim. In this study, we report, for the first time, the enhancement of the in vivo transcriptional activity of the most common Li-Fraumeni p53 mutant by imidazole-calix[6] arene through stabilization of the oligomer formation. (C) 2010 Elsevier Ltd. All rights reserved.
  • Michela Muscolini, Elisa Montagni, Silvana Caristi, Takao Nomura, Rui Kamada, Silvia Di Agostino, Marco Corazzari, Mauro Piacentini, Giovanni Blandino, Antonio Costanzo, Kazuyasu Sakaguchi, Loretta Tuosto
    CELL CYCLE 8 20 3396 - 3405 2009年10月 [査読有り][通常論文]
     
    Inactivation of the tumor suppressor p53 is central to carcinogenesis and acquisition of resistance to drug-induced apoptosis. The majority of alterations are missense mutations and occur within the DNA-binding domain. However, little is known about the point mutations in the tetramerization domain (TD). Here we investigated the properties of a new p53 mutant (Lys 351 to Asn) in the TD identified in a cisplatin-resistant ovarian carcinoma cell line (A2780 CIS). We found that K351N substitution significantly reduces the thermodynamic stability of p53 tetramers without affecting the overall half-life of the protein. Moreover, p53 K351N has a reduced ability to bind DNA and to trans-activate its specific target gene promoters, such as bax. Data obtained from the analysis of p53 subcellular localization revealed that K351N mutation inhibits the nuclear export of p53 and accumulation in the cytoplasm induced by cisplatin treatment. These results identify p53 K351N as a new cancer associated mutant with reduced tumor suppressor activity and altered functions in response to apoptotic stimuli.
  • Takao Nomura, Rui Kamada, Issaku Ito, Yoshiro Chuman, Yasuyuki Shimohigashi, Kazuyasu Sakaguchi
    BIOPOLYMERS 91 1 78 - 84 2009年01月 [査読有り][通常論文]
     
    The tumor suppressor protein p53 is a tetrameric phosphoprotein that. induces cell cycle, development, and differentiation by regulating the expression of target genes. The tetramerization of p53 is essential for its tumor suppressor functions. It has been known that oxidation of proteins affects their structure and function. A methionine residue (Met340) is located at the hydrophobic core tit p53 tetramerization domain. Here, we demonstrated that Met340 residue can be oxidized to methionine sulfoxide under oxidative conditions and investigated effects of-the oxidation of p53 tetramerization domain oil its stability and oligomerization state by CD measurement and gel filtration. The oxidation of Met340 drastically induced destabilization of the p53 tetramer by 22.8 kJ/mol of Delta Delta G (TM), while retaining the identical conformation as that of the wild-type peptide. Trypsin digestion experiments also showed that oxidation of Met340 allowed the peptide to form locally loose structure and become more sensitive to enzyme degradation. Tit(tetrameric structure may be destabilized because the oxidation of Met340 induces charge repulsion and/or steric hindrance between the sulfoxide groups. These results taken together suggested that oxidation of methionine residues tit the p53 protein might lie one of the inactivation mechanism of p53 transcriptional function under conditions of oxidative stress. (C) 2008 Periodicals, Inc. Biopolymers 91: 78-84, 2009.
  • Rui Kamada, Tomoko Terai, Takao Nomura, Yoshiro Chuman, Toshiaki Imagawa, Kazuyasu Sakaguchi
    PEPTIDES FOR YOUTH 611 567 - 568 2009年 [査読有り][通常論文]
  • Yoshiro Chuman, Hiroaki Yagi, Tomohiko Fukuda, Takao Nomura, Miho Matsukizono, Yasuyuki Shimohigashi, Kazuyasu Sakaguchi
    PROTEIN AND PEPTIDE LETTERS 15 9 938 - 948 2008年09月 [査読有り][通常論文]
     
    Protein phosphatase magnesium-dependent 1, delta (PPM1D) is a member of the PPM1 (formerly PP2C) protein phosphatase family, and is induced in response to DNA damage. The overexpression of PPM1D is thought to exert oncogenic effects through the inhibition of tumor suppressor proteins. PPM1D shows high selectivity for the primary sequence in its substrates when compared with other phosphatases, but the mechanisms underlying substrate recognition by this enzyme is not clearly known. In our present study we wished to identify the active center and further elucidate the substrate preference of PPM1D, and to this end performed sequence alignments among the human PPM1 type phosphatases. The results of this analysis clearly showed that the putative active site residues of PPM1D are highly conserved among the PPM1 family members. Phosphatase analyses using PPM1D mutants further identified the metal-chelating residues and a phosphate binding residue. In kinetic analyses using a series of phosphorylated p53 peptide analogs, the introduction of acidic residues into the region flanking the sites of dephosphorylation enhanced their affinity with PPM1D. Homology modeling of PPM1D also revealed that PPM1D contains two characteristic loops, a Pro-residue rich loop on the opposite side of the active site and a basic-residue rich loop in the vicinity of the active site in the catalytic domain. Interestingly, nonhydrolyzable AP4-3E peptides derived from the acidic p53 peptide analogs very effectively blocked PPM1D activity in an uncompetitive manner, suggesting that AP4-3E peptides may be useful lead compounds in the development of novel inhibitors of PPM1D.

MISC

担当経験のある科目(授業)

  • 物理化学II北海道大学
  • 基礎実習慶應義塾大学、北海道大学


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