Department of Biotechnology, Chonnam National University, #4-415, Gwangju, 61886, Korea.
Hygienic Safety and Analysis Center, World Institute of Kimchi, Gwangju, 61755, Korea.
Pharmacol Rep. 2020 Apr;72(2):472-480. doi: 10.1007/s43440-019-00036-7. Epub 2020 Feb 11.
N-methyl-D-aspartate (NMDA) receptor is a tetrameric protein complex composed of glycine-linked NR1 subunits and glutamate-linked NR2 subunits. There are four NR2 subunits (A-D) that differ in development, anatomy, and function profiles. They play various roles in normal and neuropathologic conditions. Specific agonists, antagonists, and modulators of subunits for selective NMDA receptors may be precious mediational tools and potent agents for treating diseases. The objective of this study was to determine the effect of poricoic acid A on NMDA receptor known to mediate excitatory synaptic transmission factors and cause changes in synaptic strength. Inhibitory effect of poricoic acid A on NR1a combined with NR2A, NR2B, NR2C, or NR2D receptor was evaluated.
Glutamate-mediated currents for each NR1a and NR2 subunits were investigated using two-electrode voltage-clamp techniques. Molecular modeling and molecular dynamics simulation studies were carried out with Autodock Tools. Poricoic acid A and NMDA receptor protein complex were examined with Ligplot and Pymol docking program. Ligplot shows binding activity at the protein and the ligand.
The inhibitory effect of poricoic acid A on glutamate-induced inward current in a concentration-dependent manner that was reversible. Half inhibitory concentrations of glutamate on NR1a/NR2A, NR1a/NR2B, NR1a/NR2C, and NR1a/NR2D receptors were 9.6 ± 1.2, 5.7 ± 0.4, 46.1 ± 21.5, and 21.5 ± 8.2 μM, respectively. This corresponded to the order of inhibitory effect of oocyte expressing NR1a and NR2s subunit of NR1a/NR2B > NR1a/NR2A > NR1a/NR2C > NR1a/NR2D.
Taken together, these results indicate that poricoic acid A can modulate the expression of NMDA receptor. In addition, the regulation of excitatory ligand-gating ion channel by poricoic acid A may have pharmaceutical functions on excitatory synaptic transmission of neuronal system.
N-甲基-D-天冬氨酸（NMDA）受体是一种由甘氨酸连接的 NR1 亚基和谷氨酸连接的 NR2 亚基组成的四聚体蛋白复合物。有四个 NR2 亚基（A-D）在发育、解剖和功能谱上有所不同。它们在正常和神经病理条件下发挥各种作用。亚基特异性激动剂、拮抗剂和调节剂可能是治疗疾病的宝贵中介工具和有效药物。本研究的目的是确定原甲酸 A 对 NMDA 受体的影响，该受体介导兴奋性突触传递因子并导致突触强度变化。评估了原甲酸 A 对 NR1a 与 NR2A、NR2B、NR2C 或 NR2D 受体结合的抑制作用。
使用双电极电压钳技术研究每个 NR1a 和 NR2 亚基的谷氨酸介导电流。采用 Autodock Tools 进行分子建模和分子动力学模拟研究。使用 Ligplot 和 Pymol 对接程序检查原甲酸 A 和 NMDA 受体蛋白复合物。 Ligplot 显示了蛋白质和配体的结合活性。
原甲酸 A 以浓度依赖的方式可逆地抑制谷氨酸诱导的内向电流。NR1a/NR2A、NR1a/NR2B、NR1a/NR2C 和 NR1a/NR2D 受体上谷氨酸的半抑制浓度分别为 9.6±1.2、5.7±0.4、46.1±21.5 和 21.5±8.2 μM。这对应于原甲酸 A 对表达 NR1a 和 NR2s 亚基的卵母细胞的抑制作用顺序为 NR1a/NR2B>NR1a/NR2A>NR1a/NR2C>NR1a/NR2D。
综上所述，这些结果表明原甲酸 A 可以调节 NMDA 受体的表达。此外，原甲酸 A 对兴奋性配体门控离子通道的调节可能对神经元系统的兴奋性突触传递具有药物作用。
