Chan Ruth, Chen Liao Y
Department of Physics, The University of Texas at San Antonio, San Antonio, TX 78249, USA.
Membranes (Basel). 2025 Sep 2;15(9):265. doi: 10.3390/membranes15090265.
Aquaglyceroporins, including human AQP7, AQP10, and GlpF, are known to facilitate movements of glycerol, water, and some other uncharged molecules across the cell membrane. In this study we focused on the transport of water molecules in the absence of glycerol for AQP7, AQP10 and GlpF using the Transition State Theory for the novel application of permeability and kinetics studies. We conducted around 500 ns of in silico simulations of the aquaglyceroporins embedded in lipid bilayer membranes with intracellular-extracellular asymmetries in leaflet lipid compositions. For the water permeability analysis, we computed the transition rate constant with correction for recrossing events where the water molecules do not completely traverse the protein channel from one side of the membrane to the other side. We also studied the hydrogen bond distributions of the single-file waters and channel residues and linear water densities along the pores of the aquaglyceroporins. Interestingly, we found that there was an inverse correlation between the number of single-file water molecules in the channel and osmotic permeability.
包括人类水甘油通道蛋白7（AQP7）、水甘油通道蛋白10（AQP10）和甘油转运蛋白（GlpF）在内的水甘油通道蛋白，已知可促进甘油、水和其他一些不带电分子跨细胞膜的转运。在本研究中，我们利用过渡态理论，将其应用于渗透性和动力学研究的新领域，重点研究了在不存在甘油的情况下，AQP7、AQP10和GlpF对水分子的转运。我们对嵌入脂质双分子层膜中的水甘油通道蛋白进行了约500纳秒的计算机模拟，这些膜的小叶脂质组成具有细胞内-细胞外不对称性。对于水渗透性分析，我们计算了过渡速率常数，并对水分子未完全从膜的一侧穿过蛋白质通道到另一侧的重新穿越事件进行了校正。我们还研究了单列水分子与通道残基之间的氢键分布以及沿水甘油通道蛋白孔的线性水密度。有趣的是，我们发现通道中单行水分子的数量与渗透渗透性之间存在负相关。
