| Project/Area Number |
04454548
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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 |
Laboratory medicine
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| Research Institution | SAITAMA MEDICAL SCHOOL |
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Principal Investigator |
KOMADA Tsugikazu SAITAMA MEDICAL SCHOOL, SCHOOL OF MEDICINE, ASSOCIATE PROFESSOR, 医学部, 助教授 (10049835)
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| Co-Investigator(Kenkyū-buntansha) |
KOYAMA Iwao SAITAMA MEDICAL SCHOOL, JUNIOR COLLEGE, ASSOCIATE PROFESSOR, 臨床検査科, 助教授 (30153688)
SAKAGISHI Yoshikatsu SAITAMA MEDICAL SCHOOL, SCHOOL OF MEDICINE, FULL PROFESSOR, 医学部, 教授 (90049768)
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| Project Period (FY) |
1992 – 1993
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| Project Status |
Completed (Fiscal Year 1993)
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| Budget Amount *help |
¥4,200,000 (Direct Cost: ¥4,200,000)
Fiscal Year 1993: ¥2,100,000 (Direct Cost: ¥2,100,000)
Fiscal Year 1992: ¥2,100,000 (Direct Cost: ¥2,100,000)
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| Keywords | ALKALINE PHOSPHATASE / GPI-ANCHOR / PEPTIDE-ANCHOR / CANCEROUS TISSUES / PUTATIVE TRANSAMIDASE / SYNTHETIC PEPTIDE / MICROSOME / MOLECULAR SIZE / ペプチドアンカー / C末端変換酵素 / 細胞下分画 / ミクロソーム分画 / ペプチド合成 / 抗疎水性アミノ酸配列抗体 / ペプチダーゼ活性 |
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| Research Abstract |
A NUMBER OF MEMBRANOUS GRYCOPROTEINS ARE ANCHORED IN THE PLASMA MEMBRANE BY A COOH-TERMINAL GLYCAN-PHOSPHATIDYLINOSITOL (GPI) MOIETY.AVAILABLE EVIDENCE INDICATES THAT THESE GPI-ANCHORED MEMBRANOUS GLYCOPROTEINS, INCLUDING ALKALINE PHOSPHATASES (ALPS), ARE INITIALLY SYNTHESIZED IN A PRECURSOR FROM CONTAINING A HYDROPHOBIC AMINO ACID SEQUENCE AT THE C-TERMINUS WHICH IS THEN PROCESSED RAPIDRY BY A PUTATIVE TRANSAMIDASE AND CONCOMITANTRY REPLACED BY THE THE GPI-MOIETY.
IN THIS PROJECT, WE MADE SEVERAL KINDS OF HYDROPHOBIC PEPTIDES AT THE C-TERMINUS OF NASCENT ALPS IN HUMAN PLACENTAL AND RAT INTESTINAL TISSUES.SITE-SPECIFIC ANTIBODIES FOR THE C-TERMINAL HYDROPHOBIC PEPTIDES WERE THEN RABBITS.THE PURIFIED ANTI-C-TERMINUS PEPTIDE IgG CAN BE EXPECTED TO SPECIFICALLY RECOGNIZE THE NASCENT ALPS BUT NOT TO REACT WITH THE GPI-ANCHORED ALPS.
THE RESULTS OBTAINDE INDICATED THAT THE NASCENT ALP WAS MINIMAL IN THE NORMAL TISSUES TESTED, WHEREAS THE NASCENT ALP WAS MARKEDLY ELEVATED IN TISSUES WELL-DIFFRENTIATED HUMAN ALVEOLAR- AND RAT GASTRIC ADENOCARCINOMA.IN CONTAST, THE REDUCED ALP MOLECULES BEARING THE GPI-ANCHOR IN THEIR CANCEROUS TISSUES WAS REVEALED BY A POLYCLONAL ANTIBODY GAINST THE GPI-MOIETY.USING A SYNTHETIC PEPITIDE ATTACHED ACROSS FROM THE C-TERMINAL PEPTIDE OF MATURE RAT INTESTINAL ALP TO THE C-TERMINAL HYDROPHOBIC PEPTIDE OF NASCENT INTESTINAL ALP, A PUTATIVE TRANSAMIDASE IN THE TESTED SUBCELLULAR FRACTIONS WASSHOWN TO BE ABUNDANT IN THE ROUGH MICROSOMAL FRACTION, BUT LESS IN THE SUPERNATANT AND MITOCHONDRIAL FRACTIONS.FURTHERMORE, BY A GEL FILTRATION OF THE DETERGENT-SOLUBILIZED MICROSOMAL FRACTION, AN APPARENT MOLECULAR SIZE OF PUTATIVE TRANSAMIDASE FOUND TO BE 110 KD.
ALL CONSIDERED, THE ELEVATED NASCENT ALPS IN CANCEROUS TISSUES AND THEIR MATURATION PROCESSING ARE GOOD MODEL FOR STUDIES ON A COMMON STRUCTURE AND FUNCTION OF GP-ANCHORED GLYCOPROTEINS.
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