Grant-in-Aid for international Scientific Research
|Allocation Type||Single-year Grants|
|Research Institution||THE UNIVERSITY OF TOKYO|
INOUE Yasuo THE UNIVERSITY OF TOKYO,PROFESSOR, 大学院・理学系研究科, 教授 (30004336)
KITAJIMA Ken THE UNIV.OF TOKYO,SENIOR RES.FELLOW, 大学院・理学系研究科, 助手 (80192558)
INOUE Sadako SHOWA UNIV., ASSOCIATED PROFESSOR, 薬学部, 助教授 (00053827)
TROY Frederic a. UNIV.OF CALIFORNIA,DAVIS,PROFESSOR, 医学部, 教授
FREDERIC A. カリフォルニア大学, 医学部, 教授
金森 審子 東京大学, 理学部, 学術振興会特別研究員
FREDERIC Tro カリフォルニア大学, 医学部, 教授
|Project Period (FY)
1992 – 1994
Completed(Fiscal Year 1994)
|Budget Amount *help
¥19,300,000 (Direct Cost : ¥19,300,000)
Fiscal Year 1994 : ¥4,100,000 (Direct Cost : ¥4,100,000)
Fiscal Year 1993 : ¥7,400,000 (Direct Cost : ¥7,400,000)
Fiscal Year 1992 : ¥7,800,000 (Direct Cost : ¥7,800,000)
|Keywords||Polysialic Acid / Deaminated Neuraminic Acid / KDN / Poly (KDN) / KDN-Transferases / Anti-poly (KDN) Monoclonal Antibody / KDN-Cleaving Enzyme (KDNase) / New Type Of Polysialic Acid / ポリシアル酸-Ca^<2+>コンプレックス / 単クローン抗体 / ポリシアル酸構造の多様性 / ウニ卵ポリシアル酸 / 抗KDN残基単クローン抗体 / α2→8-結合オリゴ・ポリKDN / KDN-複合糖質 / ポリシアル酸転移酵素 / CMP-KDN合成酵素|
Since the first demonstration of the occurrence of alpha2,8-linked polysialic acid structure in eukaryotic source in 1978 by S.Inoue and our first finding of a new type of sialic acid (KDN) in 1986, an increasing number of both polysialo- and polyKDN-glycoconjugates have been reported. The present investigation is, for its objective, (a) to search for these glycotopes in a wider variety of animal species, (b) to obtain further insight into their functional significance, and (c) to understand the basic mechanism for biosynthesis and degradation of such glycotopes, thereby developing the possible use of the enzymes involved in these processes such as alpha2,8-polysialyltransferases and varous types of KDN-transferases.
(1) Demonstration of diversity in polysialic acid structures : - We showed for the first time the presence of alpha2,8-linked poly (Neu5Ac), poly (Neu5Gc), poly (Neu5Ac, Neu5Gc), poly (KDN) and their partially acetylated forms [J.Biol.Chem.268 (1993) 23675-23684].
tion and use of ^<14>C-labeled CMP-KDN in identification of KDN-transferases : - We found the strong activity of CMP-KDN synthetase in trout testis and partially purified it to prepare CMP- [^<14>C] KDN [J.Biol.Chem.268 (1993) 2640-2648]. By use of CMP- [^<14>C] KDN as a donor substrate we were successful of identification of a KDN-transferase which specifically capped the alpha2,8-linked oligo/poly (Neu5Ac) and oligo/poly (Neu5Gc) chains [Glycoconjugate J.11 (1994) 493-499].
(3) Generation and use of immunochemical probes for KDN-glycan chains : - We first produced two different monoclonal antibodies, IgG3 subclass (mAb.kdn3G) and IgM (mAb.kdn8kdn), of which epitope structures were KDNalpha2*3Galbeta1* and alpha2*8-linked oligo/poly (KDN), respectively [Glycobiology 3 (1993) 31-36 ; Histochemistry 101 (1994) 333-340 ; Methods in Enzymology (W.J.Lennarz & G.W.Hart, Eds.) 230 (1994) 460-484]. These antibodies were successfully used as the sensitive probes in searching for KDN-glycoconjugates [Glycobiology 5 (1995) in press ; Histochemistry 101 (1994) 333-340].
(4) Calcium ion binding capacity of poly (Neu5Ac), poly (Neu5Gc), and poly (KDN) : - We determined Ca^<2+> binding constant for three different poly (Sia) chains and the observed relatively high affinity of these poly (Sia) chains toward Ca^<2+> must be relevant to the physiological role of poly (Sia) -glycoconjugates [Biochemistry 33 (1994) 1202-1208].
(5) Discovery of KDN-cleaving enzyme (KDNase) : - An enzyme hydrolyzing specifically different types of KDN-ketosidic linkages but not Neu5Acyl-ketosidic bonds was found and purified almost to homogeneity [J.Biol.Chem.269 (1994) 21415-21419]. This enzyme was particularly useful in both structural and functional studies of poly (KDN) -glycoconjugates [Science (1995) submitted].
(6) Discovery of a new class of polysialic acids : - A novel type of interketosidic linkages, [*5-O_<glycolyl>-Neu5Gcalpha2*]_n, in poly (Neu5Gc) was found in poly (Sia) -glycoprotein isolated from the jelly coat of sea urchin eggs [J.Biol.Chem.269 (1994) 22712-22718]. Less