1988 Fiscal Year Final Research Report Summary
Structure, Function and Role of Vertebrate -Galactoside-binding Lectin
| Project/Area Number |
62580133
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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 |
物質生物化学
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| Research Institution | Teikyo University |
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Principal Investigator |
KASAI Ken-ichi Faculty of Pharmaceutical Sciences, Teikyo University, 薬学部, 教授 (40001052)
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| Co-Investigator(Kenkyū-buntansha) |
HIRABAYASHI Jun Faculty of Pharmaceutical Sciences, Teikyo University, 薬学部, 助手 (40156691)
ODA Yuko Faculty of Pharmaceutical Sciences, Teikyo University, 薬学部, 助手 (30129986)
OHYAMA Yuji Faculty of Pharmaceutical Sciences, Teikyo University, 薬学部, 助手 (90129982)
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| Project Period (FY) |
1987 – 1988
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| Keywords | Lectin / -Galactoside / Chick Embryo / Human Placenta / Amino Acid Sequence / cDNA / Morphogenesis / ガン化 |
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| Research Abstract |
Since -galactoside-binding lectin is found in most vertebrates and seen to be expressed in embryonic as well as tumor tissues remarkably, it is thought to participate in fundamental biological control mechanisms not elucidated so far. We have studied it from various points of view to clarify its physiological function as well as to open the way to apply it to medical use. Firstly, we completely determined the amino acid sequence of human placenta lectin using a protein sequencer. We also succeeded in the isolation of a cDNA clone for it and determined its nucleotide sequence. A cDNA for chick 16K lectin was also cloned and most of the protein-coding region was sequenced. The primary structures including that of chick 14K type determined before were compared and shown to be highly homologous one ANO ther (e.g. human placente/chick 14K, 50% identical), and thus it is obvious that they were originated from a common ancestor protein.
The property that they do not contain any cleavable signal sequence at their N-terminus in spite of their extracellular localization is also common among them. The above human lectin cDNA was inserted into an expression vector to obtain E. coli cells that produce human lectin. They are expected to supply large amount of lectin enough to study the medical application of it. Histochemical observation using electron microscopy and anti-chick 14K lectin antibody has shown that it is distributed in and around the desmosome of epidermal cells suggesting its participation to the cell-to-cell interaction. Furthermore, studies on tumor tissues have shown that this kind of lectin also exists as a free molecule, which quite differs from that in normal tissue where most of it binds to other molecules. It is very interesting since it is suggested that the state of the lectin changes in accordance with transformation.
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