Brandan E, Inestrosa N C
J Neurosci Res. 1986;15(2):185-96. doi: 10.1002/jnr.490150208.
We have previously communicated that heparan sulfate and heparin released 16S acetylcholinesterase (AChE) from cholinergic synapses. These experiments suggest that heparan-like molecules are involved in the anchorage of AChE to the neuromuscular junction. In order to prove the in vivo interaction between the 16S AChE and heparan sulfate residues, the binding of exogenously added 16S enzyme to intact cells rich in cell-surface heparan sulfate proteoglycans was examined; 16S AChE form was shown to bind to intact endothelial cells in a specific, time-dependent, saturable fashion. A single class of binding sites was involved and at saturation around 2.52 X 10(11) molecules of 16S AChE/cm2 were bound. Fifty percent of the binding of the 16S AChE was blocked by heparan sulfate, heparin, or previous treatment of the cell with heparitinase. The binding was reversed by exogenous heparin, but not by chondroitin sulfate or hyaluronic acid. Our results demonstrate that the synaptic form of AChE binds to heparan sulfate proteoglycans on the surface of the cell.
我们之前曾报道过，硫酸乙酰肝素和肝素可从胆碱能突触中释放出16S乙酰胆碱酯酶（AChE）。这些实验表明，类硫酸乙酰肝素分子参与了AChE在神经肌肉接头处的锚定。为了证明16S AChE与硫酸乙酰肝素残基之间的体内相互作用，我们检测了外源性添加的16S酶与富含细胞表面硫酸乙酰肝素蛋白聚糖的完整细胞的结合情况；结果显示，16S AChE形式以特异性、时间依赖性和饱和性的方式与完整的内皮细胞结合。涉及单一类别的结合位点，饱和时每平方厘米约有2.52×10¹¹个16S AChE分子结合。16S AChE的50%结合被硫酸乙酰肝素、肝素或细胞预先用肝素酶处理所阻断。该结合可被外源性肝素逆转，但不能被硫酸软骨素或透明质酸逆转。我们的结果表明，AChE的突触形式与细胞表面的硫酸乙酰肝素蛋白聚糖结合。
