鲑科鱼卵的多唾液酸糖蛋白。虹鳟（Salmo gairdneri）未受精卵中200 kDa多唾液酸糖蛋白的完整结构。

Polysialoglycoproteins of Salmonidae fish eggs. Complete structure of 200-kDa polysialoglycoprotein from the unfertilized eggs of rainbow trout (Salmo gairdneri).

作者信息

Kitajima K, Inoue Y, Inoue S

出版信息

J Biol Chem. 1986 Apr 25;261(12):5262-9.

Abstract

Polysialoglycoproteins (PSGP) we first isolated from the unfertilized eggs of rainbow trout (Salmo gairderi) and now found to be a ubiquitous component of Salmonidae fish eggs are a novel type of glycoprotein. PSGP from rainbow trout has a molecular weight of 200 X 10(3), a low protein content (about 15% w/w), and a high sialic acid (N-glycolylneuraminic acid (NeuGc] content (about 60%, w/w). In any evaluation of the biological functions of PSGP, information about the complete structure of this unique macromolecular component is relevant. We have now completed the determination of the overall structural organization of the 200-kDa PSGP, and this is the first report of the complete structural analysis of this novel class of glycoprotein: (Asp)0-2-Ala-Thr*-Ser*-Glu-(Ala-Ala-Thr*-Gly-Pro-Ser-Gly-Asp-Asp-Ala-Thr -Ser- Glu)n-Ala-Ala-Thr*-Gly-Pro-Ser-Gly where * indicates the amino acid residues to which oligo- and/or polysialylglycan units are attached and n = 25. Thus the most outstanding structural features of PSGP isolated from the unfertilized eggs of rainbow trout are now the occurrence of (a) tandem repeats of a tridecapeptide and (b) an alpha-2----8-linked oligo(poly)sialyl group on each of the core oligosaccharide chains, i.e. GalNAc- beta 1----4(NeuGc alpha 2----3)GalNAc beta 1----3Gal beta 1----4Gal beta 1----3[----8NeuGc alpha 2)n----6)GalNAc alpha 1----Ser (or Thr), Fuc alpha 1----3GalNAc beta 1----3Gal beta 1----4Gal beta 1----3[----8NeuGc alpha 2)n ----6)GalNAc alpha 1----Ser (or Thr), GalNAc beta 1----3Gal beta 1----4Gal beta 1----3[----8NeuGc alpha 2)n----6)GalNAc alpha 1----Ser (or Thr), Gal beta 1----4Gal beta 1----3[----8NeuGc alpha 2)n----6)GalNAc alpha 1----Ser (or Thr), and Gal beta 1----3[----8NeuGc alpha 2)n----6) GalNAc alpha 1----Ser (or Thr).

摘要

多唾液酸糖蛋白（PSGP）最初是从虹鳟鱼（Salmo gairderi）未受精卵中分离出来的，现在发现它是鲑科鱼卵中普遍存在的一种成分，是一种新型糖蛋白。虹鳟鱼的PSGP分子量为200×10³，蛋白质含量低（约15%，w/w），唾液酸（N-羟乙酰神经氨酸（NeuGc））含量高（约60%，w/w）。在对PSGP生物学功能的任何评估中，有关这种独特大分子成分完整结构的信息都很重要。我们现已完成了200 kDa PSGP整体结构组织的测定，这是关于这类新型糖蛋白完整结构分析的首次报道：（Asp）0 - 2 - Ala - Thr* - Ser* - Glu - （Ala - Ala - Thr* - Gly - Pro - Ser - Gly - Asp - Asp - Ala - Thr* - Ser* - Glu）n - Ala - Ala - Thr* - Gly - Pro - Ser - Gly，其中*表示连接寡糖和/或多唾液酸聚糖单元的氨基酸残基，n = 25。因此，从虹鳟鱼未受精卵中分离出的PSGP最显著的结构特征是：（a）一个十三肽的串联重复序列；（b）每个核心寡糖链上有一个α - 2→8连接的寡（多）唾液酸基团，即GalNAc - β1→4（NeuGcα2→3）GalNAcβ1→3Galβ1→4Galβ1→3[→8NeuGcα2）n→6）GalNAcα1→Ser（或Thr）、Fucα1→3GalNAcβ1→3Galβ1→4Galβ1→3[→8NeuGcα2）n→6）GalNAcα1→Ser（或Thr）、GalNAcβ1→3Galβ1→4Galβ1→3[→8NeuGcα2）n→6）GalNAcα1→Ser（或Thr）、Galβ1→4Galβ1→3[→8NeuGcα2）n→6）GalNAcα1→Ser（或Thr）以及Galβ1→3[→8NeuGcα2）n→6）GalNAcα1→Ser（或Thr）。