Department of Clinical Chemistry and Transfusion Medicine, The Sahlgrenska Academy at University of Gothenburg, Sahlgrenska University Hospital, Gothenburg, Sweden.
Glycobiology. 2011 Feb;21(2):162-74. doi: 10.1093/glycob/cwq143. Epub 2010 Oct 6.
Glycolipids from the red cells of a rare blood group A subgroup individual, expressing the blood group A(3) phenotype with the classical mixed-field agglutination phenomenon, A(2(539G>A))/O(1) genotype, and an unusual blood group A glycolipid profile, were submitted to a comprehensive biochemical and structural analysis. To determine the nature of blood group A glycolipids in this A(3) phenotype, structural determination was carried out with complementary techniques including proton nuclear magnetic resonance (1D and 2D), mass spectrometry (MS) (nano-electrospray ionization/quadrupole time-of-flight and tandem mass spectrometry) and thin layer chromatography with immunostaining detection. As expected, total blood group A structures were of low abundance, but contrary to expectations extended-A type 2 and A type 3 glycolipids were more dominant than A hexaglycosylceramides based on type 2 chain (A-6-2 glycolipids), which normally is the major A glycolipid. Several para-Forssman (GalNAcβ3GbO(4)) structures, including extended forms, were identified but surmised not to contribute to the classic mixed-field agglutination of the A(3) phenotype. It is proposed that the low level of A antigen combined with an absence of extended branched glycolipids may be the factor determining the mixed-field agglutination phenomenon in this individual.
从一个罕见的 A 亚型个体的红细胞中提取的糖脂，具有经典的混合场凝集现象、A(2(539G>A))/O(1) 基因型和不寻常的 A 血型糖脂谱，表达 A(3)表型，进行了全面的生化和结构分析。为了确定这种 A(3)表型中 A 血型糖脂的性质，采用质子核磁共振（1D 和 2D）、质谱（MS）（纳升电喷雾/四极杆飞行时间和串联质谱）和薄层层析与免疫染色检测等互补技术进行了结构测定。正如预期的那样，总 A 血型结构的丰度较低，但与预期相反，基于 2 型链的延长 A 型 2 和 A 型 3 糖脂比 A 六糖神经酰胺更为丰富（A-6-2 糖脂），后者通常是主要的 A 血型糖脂。鉴定了几种 Para-Forssman（GalNAcβ3GbO(4)）结构，包括扩展形式，但推测它们不会导致 A(3)表型的经典混合场凝集。据推测，低水平的 A 抗原结合缺乏扩展分支糖脂可能是决定该个体混合场凝集现象的因素。
