Graduate School of Pharmaceutical Sciences, Nagoya City University, 3-1 Tanabe-dori, Mizuho-ku, Nagoya 467-8603, Japan.
Carbohydr Res. 2010 Feb 11;345(3):442-8. doi: 10.1016/j.carres.2009.12.002. Epub 2009 Dec 11.
To understand the roles of species-specific carbohydrates, systematic studies of interspecific glycan analyses are imperative. An extensive series of glycomics studies on approximately 180 kinds of bird eggs have demonstrated that 60-70% of the birds, which are closely related in phylogeny, express the alpha-Galp-(1-->4)-Galp structure on their egg glycoproteins. This prompted us to investigate the glycosylation profiles of eggs from an evolutionarily related organism, a sea turtle (reptilian). We performed N-glycosylation profiling of turtle egg yolk by using HPLC mapping in conjunction with mass spectrometric methods and thereby demonstrated that the alpha-Galp-(1-->4)-Galp groups are displayed on approximately 38% of total N-glycans. Our findings suggest that the ability to express the galabiose structure was acquired at an early stage of diversification in amniotes.
为了理解物种特异性碳水化合物的作用，对种间糖链分析进行系统研究是至关重要的。对大约 180 种鸟类蛋的广泛糖组学研究表明，在系统发生上密切相关的 60-70%鸟类在其卵糖蛋白上表达α-Galp-(1-->4)-Galp 结构。这促使我们研究与进化上相关的生物——海龟（爬行动物）的卵的糖基化图谱。我们通过 HPLC 图谱结合质谱方法对龟卵蛋黄的 N-糖基化进行了分析，从而证明了α-Galp-(1-->4)-Galp 基团大约占总 N-聚糖的 38%。我们的发现表明，在羊膜动物多样化的早期阶段就获得了表达半乳糖二糖结构的能力。
