| Project/Area Number |
63490018
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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 |
広領域
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| Research Institution | Showa University |
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Principal Investigator |
INOUE Sadako Showa Univ. Parmaceut.Sci., Assoc. Prof., 薬学部, 助教授 (00053827)
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| Co-Investigator(Kenkyū-buntansha) |
IWASAKI Mariko Showa Univ. Parmaceut.Sci., Assistant, 薬学部, 助手 (80054021)
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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 |
¥3,400,000 (Direct Cost: ¥3,400,000)
Fiscal Year 1989: ¥600,000 (Direct Cost: ¥600,000)
Fiscal Year 1988: ¥2,800,000 (Direct Cost: ¥2,800,000)
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| Keywords | Cortical Alveolar Glycoproteins / Polysialoglycoproteins / Hyosophorin / KDN-glycoproteins / Oligo / PolyKDN / Deaminated Neuraminic Acid / Free N-glycans / Vitellogenesis / KDNー糖タンパク質 / リン酸化糖タンパク質 / 糖タンパク質糖鎖の構造と機能 / 魚卵表層胞局在糖タンパク質 / 魚卵初期発生 / 糖タンパク質糖鎖の遊離と蓄積 |
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| Research Abstract |
1. Cortical Alveolar Glycoproteins (Hyosophorin). Polysialoglycoprotein (PSGP) of rainbow trout eggs is a cortical alveolar component and is anticipated to have an important function during fertilization and/or early development (1978-1987).
We have shown the tandemly repeating sequences of apoPSGPs of Salmonidae to be genus-specific. We have also shown cortical alveolar glycoproteins (hyosophorin) from non-salmon fish eggs (Oryzia latipes, Plecoglossus altivelis, and Paralichthys olivaceus), and revealed these hyosophorins (ca. 100 kDa) to have tandemly repeating structure and to be depolymerized to the repeating structure upon fertilization. These non-salmon hyosophorins have N-linked pentaantennary carbohydrate units in sharp contrast to salmon hyosophorins (PSGPs). Carbohydrate units of hyosophorin molecules of sea-water spawning fish are not acidic whereas those of fresh-water spawning fish are highly sialylated (polyanionic), suggesting that hyosophorin may be involved in regulati
… More
ng water-salt exchange between the perivitelline fluid of the fertilized eggs and the external medium to maintain suitable osmotic and ionic environment for developing embryo.
2. KDN-Glycoproteins. KDN is a naturally occurring deaminated neuraminic acid discovered in salmon PSGP as a minor component. Now we isolated KDN-rich glycoproteins (KDN-gp) that contain no sialic acid but have only KDN as much as 50%(w/w) from the vitelline envelope (VE) of the eggs and the ovarian fluid of ovulating rainbow trout. The carbohydrate units of KDN-gp contain alpha-2,8-linked oligo/polyKDN chains (n = 2-10). KDN-gp of the VE was localized in the second layer and in the most outer surface at the micropyle region, suggesting the KDN-gp to serve as a possible sperm attractant.
3. Occurrence and Origin of Glycoprotein-derived Free Sialooligosaccharides in Fish Eggs. We found free sialooligosaccharides accumulated in some fish eggs and showed that they are derived from glycoproteins by cleavage with a putative PNGase hitherto unreported for animal cells. We also showed that the free oligosaccharides are released from phosvitins during vitellogenesis as judged from their carbohydrate structures. Less
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