Bartos E M, Glinos A D
J Cell Biol. 1976 Jun;69(3):638-46. doi: 10.1083/jcb.69.3.638.
We have previously reported the presence and regulation of an acetylcholine-hydrolyzing enzyme in high density suspension cultures of WRL-10A fibroblasts where its activity increases 100-fold when growth is arrested. Substrate specificity, substrate inhibition, and product identification studies indicate that this enzyme is acetylcholinesterase (AChE, EC 3.1.1.7). Treatment of whole cells with 5 mM diazotized sulfanilic acid revealed that most of the AChE is located on the external surface of the cell membrane. It was also found that the enzyme is released in the medium at a rate of 0.5 U/h/mg cell protein and that within a 24-h period the de novo synthesized and liberated AChE is equivalent to 90% of the activity associated with the cells. No similar synthesis of AChE was found in six order fibroblastic cell lines examined. These and related findings indicating that acetylcholine is also present in high density populations of WRL-10A cells suggest that this unique phenotype may be used profitably in exploring further the relationship between components of the cholinergic system and non-neuronal cell growth.
我们之前报道过，在WRL - 10A成纤维细胞的高密度悬浮培养物中存在一种乙酰胆碱水解酶及其调节情况，当细胞生长停滞时，其活性会增加100倍。底物特异性、底物抑制和产物鉴定研究表明，这种酶是乙酰胆碱酯酶（AChE，EC 3.1.1.7）。用5 mM重氮化磺胺酸处理全细胞发现，大部分AChE位于细胞膜外表面。还发现该酶以0.5 U/h/mg细胞蛋白的速率释放到培养基中，并且在24小时内，新合成并释放的AChE相当于与细胞相关活性的90%。在所检测的六种成纤维细胞系中未发现类似的AChE合成。这些以及相关发现表明WRL - 10A细胞的高密度群体中也存在乙酰胆碱，这表明这种独特的表型可能有助于进一步探索胆碱能系统成分与非神经元细胞生长之间的关系。
