Kyushu University Academic Staff Educational and Research Activities Database
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Akinori Hirashima Last modified date:2018.09.03

Associate Professor / Division of Molecular Biosciences
Department of Bioscience and Biotechnology
Faculty of Agriculture


Graduate School
Undergraduate School
Administration Post
Other


E-Mail
Homepage
http://133.5.200.186/hso.html
Phone
092-642-2856
Fax
092-642-2856
Academic Degree
Doctor (Agriculture)
Field of Specialization
Biological Chemistry and Bioorganic Chemistry
Outline Activities
In drug discovery, it is common to have measured activity data for a set of compounds acting upon a particular protein but not to have knowledge of the three-dimensional structure of the protein active site. In the absence of such three-dimensional information, one can attempt to build a hypothetical model of the receptor site that can provide insight about receptor-site characteristics. Such analyses are known as a comparative receptor surface analysis (CoRSA) and a molecular-field analysis (MFA), which provide compact and quantitative descriptors which capture three-dimensional information about a putative receptor site. Meanwhile pharmacophore models are qualitative and capture information about the commonality of compounds that bind. Agonists for tyramine (TA) reseceptor were tested for inhibitory specificity observing calling behavior and using a modified radiochemical bioassay to monitor de novo pheromone production in Plodia interpunctella. A set of 70 agonists and a set of 20 antagonists for octopamine (OA) receptor 3 in locust nervous tissue and of a set of 40 agonists against OA receptor 2 in cockroach nervous tissue were selected as study sets. The result may imply that the process of these molecular modeling treat the structures reasonably. The molecular modeling could provide useful information in the characterization and differentiation of TA and OA receptors. They may help to point the way towards developing extremely potent and relatively specific TA and OA ligands, leading to potential insecticides, although further research on the comparison of the 3D molecular modeling is necessary.
Research
Research Interests
  • Biogenic amines are common biologically active substances spread within the whole animal kingdom where they play important roles as messengers and regulators of cell functions. The insect nervous system contains such biogenic amines as octopamine (OA), which is synthesized from tyramine (TA) by the catalysis of tyramine-β-hydroxylase (TβH). Both tyramine and octopamine act as a neurotransmitters, neurohormones and neuromodulators in the arthropod nervous system. In this study, the Drosophila 70 kDa tyramine-β-hydroxylase (DmTβH) is purified after the recombinant nucleopolyhedrovirus isolated from Bombyx mori (BmNPV) containing the TβH gene is injected into the hemocoel of the fifth instar larvae from the d17 B. mori strain and 1-(2, 5-dimethoxyphenyl) imidazole-2(3H)-thione (HRTs) are used to detect the inhibitory activity against DmTβH. Radiolabelled 3H-TA was used to analyze the activity of inhibitor compounds using liquid scintillation counter. The inhibitory experiments using different concentration of HRT showed that DmTβH is inhibited dose dependently at pH 7.6 and 25 °C during a 30 min of incubation. The ID50 values of HRT measured by probit method is 0.0033 µM at 95 % confidence interval (0.0002 µM - 0.0194 µM) which shows the potential inhibitory activity against DmTβH.
    keyword : octopamine, tyramine, receptor, drug design
    2001.09~2022.03.
  • Clarification of stress reaction and drug design of ligands for octopamiine/tyramine receptors
    keyword : sex pheromone, stress, octopamine, tyramine, pharmacophore model. structure-activity relationship
    2000.01~2022.03In drug discovery, it is common to have measured activity data for a set of compounds acting upon a particular protein but not to have knowledge of the three-dimensional structure of the protein active site. In the absence of such three-dimensional information, one can attempt to build a hypothetical model of the receptor site that can provide insight about receptor-site characteristics. Such analyses are known as a comparative receptor surface analysis (CoRSA) and a molecular-field analysis (MFA), which provide compact and quantitative descriptors which capture three-dimensional information about a putative receptor site. Meanwhile pharmacophore models are qualitative and capture information about the commonality of compounds that bind. Agonists for tyramine (TA) reseceptor were tested for inhibitory specificity observing calling behavior and using a modified radiochemical bioassay to monitor de novo pheromone production in Plodia interpunctella. A set of 70 agonists and a set of 20 antagonists for octopamine (OA) receptor 3 in locust nervous tissue and of a set of 40 agonists against OA receptor 2 in cockroach nervous tissue were selected as study sets. The result may imply that the process of these molecular modeling treat the structures reasonably. The molecular modeling could provide useful information in the characterization and differentiation of TA and OA receptors. They may help to point the way towards developing extremely potent and relatively specific TA and OA ligands, leading to potential insecticides, although further research on the comparison of the 3D molecular modeling is necessary..
Academic Activities
Membership in Academic Society
  • the Entomological society of Korea
  • The Science Advisory Board
  • Japan Society for Bioscience, Biotechonolgy and Agrochemistry
  • Pesticide Science Society of Japan
Awards
  • Screening for inhibitor of recombinant Drosophila melanogaster tyramine-β-hydroxylase
  • For my valuable contribution and dedicated service in the peer review of manuscripts submitted to ACS journals
  • 学外
  • 学外