| Project/Area Number |
63480128
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| Research Category |
Grant-in-Aid for General Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Research Field |
General medical chemistry
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| Research Institution | The University of Tokushima |
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Principal Investigator |
KATUNUMA N Institute for Enzyme Research, The University of Tokushima, Professor, 酵素科学研究センター, 教授 (50035375)
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| Co-Investigator(Kenkyū-buntansha) |
II K The University of Tokushima, School of Medicine Assistant Professor, 医学部, 助教授 (50035507)
KOMINAMI E Juntendo University School of Medicine, Professor, 医学部, 教授 (10035496)
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| Project Period (FY) |
1988 – 1989
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| Project Status |
Completed (Fiscal Year 1989)
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| Budget Amount *help |
¥6,200,000 (Direct Cost: ¥6,200,000)
Fiscal Year 1989: ¥1,800,000 (Direct Cost: ¥1,800,000)
Fiscal Year 1988: ¥4,400,000 (Direct Cost: ¥4,400,000)
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| Keywords | Cathepsin / Lysosomes / Intracellular processing / Macrophages / cDNA cloning / リソゾーム / システインプロテアーゼ / カテプシン B / カテプシン H / カテプシン L |
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| Research Abstract |
Inatracellular targeting of lysosomal cysteine proteinases to lysosomes was studied with cultured macrophages. Cathepsins B, H and L were found to be as proenzymes in Golgi apparatus, and then as the single chain mature enzymes in lysosomes. Metallo-proteinase inhibitors and pepstatin retarded the conversion of proenzymes to mature enzymes. Short pulse-chase experiment showed the detection of intermediates during the conversion, suggesting that different proteinases operate in the conversion process. cDNA cloning and sequencing of cathepsin H and L were carried out and amino acid sequences of pre-propeptides of enzymes were deduced. Immunoelectron microscopic studies with antibodies specific for procathepsins showed that mature enzymes were detected in lysosomes, and that proenzymes were localized in Golgi apparatus. It is under investigation what forms of enzymes are present in prelysosomes. More than 30% of procathepsins synthesized was excreted to the medium without reaching to lysosomes. Morphologically, small vesides labeled by anticathepsin L were detected, suggesting that those are in secretory route.
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