Vilela-Silva A C, Alves A P, Valente A P, Vacquier V D, Mourão P A
Laboratório de Tecido Conjuntivo, Hospital Universitário and Departamento de Bioquímica Médica, Centro de Ciências da Saúde, Universidade Federal do Rio de Janeiro, Caixa Postal 68041, Rio de Janeiro, RJ, 21941-590, Brazil.
Glycobiology. 1999 Sep;9(9):927-33. doi: 10.1093/glycob/9.9.927.
The egg jelly coats of sea urchins contains sulfated polysaccharides responsible for inducing the sperm acrosome reaction which is an obligatory event for sperm binding to, and fusion with, the egg. Here, we extend our study to the sea urchin Strongylocentrotus franciscanus. The egg jelly of this species contains a homofucan composed of 2- O -sulfated, 3-linked units which is the simplest structure ever reported for a sulfated fucan. This polysaccharide was compared with other sulfated alpha-L-fucans as inducers of acrosome reaction in conspecific and heterospecific sperm. Although all these fucans are linear polymers composed of 3-linked alpha-L-fucopyranosyl units, they differ in the proportions of 2-O- and 4-O-sulfation. The reactivity of the sperm of each species is more sensitive to the egg jelly sulfated fucan found in their own species. The reactivity of the sperm does not correlate with the charge density of the fucan, but with the proportion of 2-O- and 4-O-sulfation. The pattern of sulfation may be an important feature for recognition of fucans by the sperm receptor contributing to the species-specificity of fertilization.
海胆的卵胶膜含有硫酸化多糖，这些多糖可诱导精子顶体反应，而顶体反应是精子与卵子结合并融合所必需的过程。在此，我们将研究扩展至加州海胆。该物种的卵胶膜含有一种同型岩藻聚糖，由2-O-硫酸化的3-连接单元组成，这是迄今报道的硫酸化岩藻聚糖中最简单的结构。将这种多糖与其他硫酸化α-L-岩藻聚糖作为同种和异种精子顶体反应的诱导剂进行了比较。尽管所有这些岩藻聚糖都是由3-连接的α-L-岩藻吡喃糖基单元组成的线性聚合物，但它们在2-O-硫酸化和4-O-硫酸化的比例上有所不同。每个物种的精子对自身物种卵胶膜中的硫酸化岩藻聚糖反应更敏感。精子的反应性与岩藻聚糖的电荷密度无关，而是与2-O-硫酸化和4-O-硫酸化的比例有关。硫酸化模式可能是精子受体识别岩藻聚糖的一个重要特征，有助于受精的物种特异性。
