Szemes Áfonya, Lajkó Eszter, Láng Orsolya, Kőhidai László
Department of Genetics, Cell- and Immunobiology, Semmelweis University, Nagyvarad ter 4, Budapest, H-1089, Hungary.
Department of Genetics, Cell- and Immunobiology, Semmelweis University, Nagyvarad ter 4, Budapest, H-1089, Hungary.
Carbohydr Res. 2015 Apr 30;407:158-65. doi: 10.1016/j.carres.2015.02.009. Epub 2015 Mar 2.
Chemotaxis is one of the most essential cell physiological responses, which was developed in parallel the molecular evolution of signal molecules. Previously good correlations were found between chemotactic moieties and physicochemical properties (SEA, solubility, pKa) of peptide type ligands in Tetrahymena model. However, references are rather weak in eukaryotic chemotaxis about significance of simple carbohydrates. In the present work our goal is (i) to investigate the chemotactic effect of 10 mono- and disaccharides in the eukaryotic Tetrahymena pyriformis; (ii) to describe effective ligands with physicochemical parameters; (iii) to test whether sugars are acting via induction of metabolic pathways. Our results are: (i) the tested sugars can trigger both significant attractant (D-glucose, D-mannose) and significant repellent (D-glucosamine, D-fructose, N-acetyl-D-galactosamine, D-arabinose) effects, while some of the sugars (maltose, lactose, sucrose, D-galactose) had no effect. (ii) Correlations were described between the chemotactic effectiveness of the ligands and their physicochemical characters (TPSA, XLogP), which are supposed to influence the internalization of the sugars. (iii) All ligands proved to have low selection potential, which refers to a 'short-term' receptor moiety or influencing specific metabolic pathways. (iv) Starvation elicited modified, strong chemoattractive responsiveness towards glucose; however, it was independent of concentration while 1 h insulin treatment resulted in an increased and concentration dependent chemotaxis induced by glucose.
趋化性是最基本的细胞生理反应之一，它与信号分子的分子进化并行发展。此前在四膜虫模型中发现肽类配体的趋化部分与物理化学性质（表面可及面积、溶解度、pKa）之间存在良好的相关性。然而，在真核生物趋化性中，关于单糖的重要性的参考文献相当匮乏。在本研究中，我们的目标是：（i）研究10种单糖和二糖对真核生物梨形四膜虫的趋化作用；（ii）用物理化学参数描述有效配体；（iii）测试糖类是否通过诱导代谢途径发挥作用。我们的结果如下：（i）所测试的糖类既能引发显著的吸引作用（D-葡萄糖、D-甘露糖），也能引发显著的排斥作用（D-葡萄糖胺、D-果糖、N-乙酰-D-半乳糖胺、D-阿拉伯糖），而有些糖类（麦芽糖、乳糖、蔗糖、D-半乳糖）没有作用。（ii）描述了配体的趋化有效性与其物理化学特征（拓扑表面积、辛醇/水分配系数）之间的相关性，这些特征被认为会影响糖类的内化。（iii）所有配体都显示出较低的选择潜力，这表明存在一个“短期”受体部分或影响特定的代谢途径。（iv）饥饿引发了对葡萄糖的改变的、强烈的化学吸引反应；然而，这与浓度无关，而1小时的胰岛素处理导致葡萄糖诱导的趋化性增加且呈浓度依赖性。
