| Project/Area Number |
61571042
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
Biological pharmacy
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| Research Institution | Hokkaido University |
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Principal Investigator |
NAKAYAMA Hitoshi Fac. of Pharmaceutical Sciences, Hokkaido University, 薬学部, 助手 (70088863)
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| Co-Investigator(Kenkyū-buntansha) |
HATANAKA Yasumaru Fac. of Pharmaceutical Sciences, Hokkaido University, 薬学部, 教務職員 (30111181)
TANIZAWA Kazutaka Fac. of Pharmaceutical Sciences, Hokkaido University, 薬学部, 助教授 (90001049)
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| Project Period (FY) |
1986 – 1987
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| Project Status |
Completed (Fiscal Year 1987)
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| Budget Amount *help |
¥2,100,000 (Direct Cost: ¥2,100,000)
Fiscal Year 1987: ¥500,000 (Direct Cost: ¥500,000)
Fiscal Year 1986: ¥1,600,000 (Direct Cost: ¥1,600,000)
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| Keywords | Sodium Channel Structure Function / Photoaffinity Labeling / Antibodies / 抗ペプチド抗体 / 糖鎖結合部位 / ナトリウムチャンネル / トポロジー / テトロドトキシン / 糖ペプチド |
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| Research Abstract |
As an approach to reveat the molecular architecture of the functional components in the sodium channel,we have applied three different methods. We achieved most of the project purpose during past two years and have found a clue to a new development in this field.
1) Photoaffinity Labeling with Tetrodotoxin Derivatives:
Four photoactivable tetrodotoxin (TTX) derivatives were synthesized. All the compounds show comparable affinities to TTX itself, though the extents of photoincorporation and their stabilities during purification are markedly ditterent. Judged from several points of criteria, we have chosen the compound containing a phenyldiazirine is most suitable one. Frther study with the compound is now in progress.
2) Topological Mapping of the Channel Molecules Using Anti-Peptide Antibodies:
Three peptides corresponding to the defined regions of the sodium channel were synthesized and antibodies against the peptides were raised. By the immunochemical analysis C-terminus region is located on the cytoplasmic surface on the eel membrane and S4 segment, a voltage sensor, must be located at inner pore in a highly ordered structure. A part of the N-terminus is suggested unexpectedly at the extracellular surface.
3) Identification of the Glycosylated Sites:
After tryptic digestion, some glycoepptides of the channel protein were isolated. One of them is identified at position 1194 to 1213,which contains a mucin-type oligosaccharide on a Ser or Thr residue. The other is assumend to be a peptide near C-terminus, but it is contradicted to currently proposed models. Confirmative experiments are required.
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