Division of Molecular Biosciences, Faculty of Natural Sciences, Imperial College London, SW7 2AZ, UK.
Science. 2011 Sep 23;333(6050):1761-4. doi: 10.1126/science.1207438. Epub 2011 Aug 18.
Human fertilization begins when spermatozoa bind to the extracellular matrix coating of the oocyte, known as the zona pellucida (ZP). One spermatozoan then penetrates this matrix and fuses with the egg cell, generating a zygote. Although carbohydrate sequences on the ZP have been implicated in sperm binding, the nature of the ligand was unknown. Here, ultrasensitive mass spectrometric analyses revealed that the sialyl-Lewis(x) sequence [NeuAcα2-3Galβ1-4(Fucα1-3)GlcNAc], a well-known selectin ligand, is the most abundant terminal sequence on the N- and O-glycans of human ZP. Sperm-ZP binding was largely inhibited by glycoconjugates terminated with sialyl-Lewis(x) sequences or by antibodies directed against this sequence. Thus, the sialyl-Lewis(x) sequence represents the major carbohydrate ligand for human sperm-egg binding.
人类受精始于精子与卵母细胞外基质涂层（即透明带）的结合。然后，一个精子穿透这个基质并与卵细胞融合，形成受精卵。虽然 ZP 上的碳水化合物序列与精子结合有关，但配体的性质尚不清楚。在这里，超灵敏的质谱分析显示，唾液酸化-Lewis(x)序列[NeuAcα2-3Galβ1-4(Fucα1-3)GlcNAc]，一种众所周知的选择素配体，是人类 ZP 中 N-和 O-聚糖上最丰富的末端序列。糖缀合物末端带有唾液酸化-Lewis(x)序列或针对该序列的抗体，可显著抑制精子与 ZP 的结合。因此，唾液酸化-Lewis(x)序列代表了人类精卵结合的主要碳水化合物配体。
