Parish C R, Jakobsen K B, Coombe D R, Bacic A
Division of Cell Biology, John Curtin School of Medical Research, Australian National University, Canberra.
Biochim Biophys Acta. 1991 Jan 23;1073(1):56-64. doi: 10.1016/0304-4165(91)90182-g.
Previous studies suggested that cell adhesion in the marine sponge, Ophlitaspongia tenuis, is mediated by a 35 kDa cell surface protein which interacts with an extracellular sulfated polysaccharide. This paper describes a simple and efficient procedure for isolating both putative cell adhesion molecules from detergent lysates of O. tenuis cells, the procedure being based on the fortuitous affinity of the sponge polysaccharide for heparin. The purified polysaccharide inhibits O. tenuis sponge cell aggregation, is highly sulfated and represents a glycosaminoglycan containing glucuronic acid. N-sulfated glucosamine and, possibly, glucose. The purified 35 kDa protein has a high affinity for the sponge polysaccharide and also, selectively interacts with dextran sulfate, a polysaccharide that has been shown previously to both bind to the sponge cell surface and inhibit aggregation of O. tenuis cells. Collectively, the data supports the hypothesis that the 35 kDa molecule is the major cell adhesion protein in O. tenuis. Preliminary data also suggests that the sponge contains an endogenous glycan hydrolase which can cleave the sponge polysaccharide.
先前的研究表明，海洋海绵纤细奥菲海绵（Ophlitaspongia tenuis）中的细胞黏附是由一种35 kDa的细胞表面蛋白介导的，该蛋白与一种细胞外硫酸化多糖相互作用。本文描述了一种从纤细奥菲海绵细胞的去污剂裂解物中分离这两种假定的细胞黏附分子的简单高效方法，该方法基于海绵多糖对肝素的偶然亲和力。纯化的多糖可抑制纤细奥菲海绵细胞聚集，高度硫酸化，是一种含有葡萄糖醛酸、N-硫酸化葡糖胺以及可能还有葡萄糖的糖胺聚糖。纯化的35 kDa蛋白对海绵多糖具有高亲和力，并且还与硫酸葡聚糖选择性相互作用，硫酸葡聚糖是一种先前已被证明既能结合到海绵细胞表面又能抑制纤细奥菲海绵细胞聚集的多糖。总体而言，这些数据支持了35 kDa分子是纤细奥菲海绵中主要细胞黏附蛋白的假说。初步数据还表明，该海绵含有一种内源性聚糖水解酶，它可以切割海绵多糖。
