| Co-Investigator(Kenkyū-buntansha) |
TAKESUE Yoshiki Gifu Univ., Fac. Gen. Educ., Professor, 教養部, 教授 (50023651)
TOMITA Motowo Showa Univ., Sch. Pharm. Sci., Professor, 薬学部, 教授 (30102370)
IKEHARA Yukio Fukuoka Univ., Sch. Med. Professor, 医学部, 教授 (70037612)
NAKASHIMA Izumi Nagoya Univ., Sch. Med., Professor, 医学部, 教授 (40022826)
KITO Makoto Kyoto Univ., Res. Inst. Food Sci., Professor, 食糧科学研究所, 教授 (60027183)
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| Research Abstract |
The primary structures of 5'-nucleotidase from bovine liver, rat liver and human placenta were determined and the 25-amino acid sequences of signal peptides for the attachment of GPI-anchor precursor were identified. By cloning and sequencing of cDNAs and treatment with PIPLC, the elongation factor EF-1alpha, a homologous restriction factor MACIF and a tumor marker antigen CA-125 were confirmed to be anchored by phosphatidylinositol. Also, trehalase, a GPI-anchored enzyme on the brush-border membranes of mammalian intestine and kidney, proved not to be a carrier for glucose transport. On the one hand, aminopeptidase N liberated by the action of PIPLC, was highly purified, characterized and determined for its substrate specificity. In KB III cells, alkaline phospho-diesterase I, a well-known PI-anchored enzyme, was shown to be induced at high level by sodium butyrate. The sensitivity of Thy-1 and other GPI-anchored proteins to PIPLC were different in every lymphoid tissue and every strains of lymphoma cells ; especially, Thy-1 in thymocytes were proved to be PIPLC-resistant in that the inositol moiety in the anchor is acylated. It was suggested that Thy-1 in thymocytes as well as DAF (decay-accelerating factor) in monocytes and macrophages might play an important role in the intracellular signal transduciton. The case study for 8 PNH (paroxysmal nocturnal hemoglobinuria) patients on the deficiency of GPI-anchored antigens such as DAF, CD14, CD16 and CD59 revealed that the ex pressions of CD14 and CD16 were extremely low in many patients, while CD59 but not DAF was completely deficient in one of the patients. On the one hand, the monoclonal antibodies for alkaline phosphatase which is a tumor marker in the bone, were established as an opening for serum diagnosis of bone tumor.
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