Structures of unique globoside elongation products present in erythrocytes with a rare NOR phenotype.
Structures of unique globoside elongation products present in erythrocytes with a rare NOR phenotype.
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红细胞中存在的独特球苷延伸产物的结构具有罕见的 NOR 表型。
DOI：
10.1093/glycob/cwl071
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发表时间：
2007
期刊：
影响因子：
4.3
通讯作者：
Lisowska,Elwira
中科院分区：
文献类型：
--
作者：
Duk,Maria;Singh,Suddham;Reinhold,VernonN;Krotkiewski,Hubert;Kurowska,Ewa;Lisowska,Elwira
发现罕见的NOR表型多凝集红细胞含有两种独特的鞘糖脂（命名为NOR 1和NOR 2）。这些成分（在正常红细胞中未检测到）与Griffonia simplicifoliaisolectin IB 4（GSL-IB 4）反应，通常存在人抗NOR抗体。据报道，NOR 1组分是一种含有单个半乳糖残基的球糖苷，该半乳糖残基与末端N-乙酰半乳糖胺连接。在这里，我们报告的第二个糖脂，NOR 2，和第三个新的组件迁移在高效薄层色谱（HPTLC）NOR 1和NOR 2之间的结构研究。通过离子阱顺序质谱（MALDI-QIT-TOF）和用糖苷酶分步处理的组合确定结构，然后在HPTLC板上用凝集素和小鼠单克隆抗NOR抗体鉴定产物。NOR 2组分是NOR 1的二糖延伸，具有以下结构：Galα1-4GalNAcβ1 - 3Galα1-4GalNAc β 1-3Galα1-4Galβ1-4Glcβ1-Cer。用α-半乳糖苷酶处理NOR 2得到在NOR 1和NOR 2之间迁移的糖脂，其不与GSL-IB 4或抗NOR抗体反应，但与GalNAc特异性大豆凝集素反应。这种中间糖脂（现命名为NORint）被鉴定为NOR红细胞中性糖脂部分的相对丰富的组分，表明其作为NOR 2的前体存在。NORint的结构也通过连续质谱研究得到证实。这些结果表明，NOR受试者中的多聚凝集是由于通过将Galα 1，4和GalNAcβ 1，3依次添加到球蛋白糖苷中合成的独特红细胞糖脂所致。
Rare polyagglutinable erythrocytes of NOR phenotype were found to contain two unique glycosphingolipids (designated NOR1 and NOR2). These components (not detected in normal erythrocytes) were reactive withGriffonia simplicifoliaisolectin IB4 (GSL-IB4) and commonly present human anti-NOR antibodies. The NOR1 component has been reported to be a globoside containing a single galactose residue linked α1,4 to the terminal N-acetylgalactosamine. Here, we report the structural studies on a second glycolipid, NOR2, and a third novel component migrating in high-performance thin-layer chromatography (HPTLC) between NOR1 and NOR2. The structures were determined by a combination of ion trap sequential mass spectrometry (MALDI-QIT-TOF) and step-wise treatment with glycosidases, followed by identification of products on HPTLC plates with lectins and mouse monoclonal anti-NOR antibody. The NOR2 component was found to be a disaccharide extension of NOR1 with the following structure: Galα1-4GalNAcβ1-3Galα1-4GalNAcβ1-3Galα1-4Galβ1-4Glcβ1-Cer. Treatment of NOR2 with α-galactosidase gave a glycolipid migrating between NOR1 and NOR2, which did not react with either GSL-IB4 or anti-NOR antibodies but did react with GalNAc-specific soybean agglutinin. This intermediate glycolipid (now designated NORint) was identified as a relatively abundant component of a neutral glycolipid fraction from NOR erythrocytes, suggesting its presence as a precursor to NOR2. The structure of NORintwas also confirmed by sequential mass spectrometry studies. These results indicate that polyagglutination in NOR subjects is due to unique erythrocyte glycolipids that are synthesized by sequential addition of Galα1,4 and GalNAcβ1,3 to globoside.