Chem. J. Chinese Universities ›› 2021, Vol. 42 ›› Issue (8): 2550.doi: 10.7503/cjcu20210106

• Physical Chemistry • Previous Articles     Next Articles

Prediction of the Binding Site of PIP2 in the TREK-1 Channel Based on Molecular Modeling

LEI Xiaotong, JIN Yiqing, MENG Xuanyu()   

  1. School of Radiation Medicine and Protection,Institute of Quantitative Biology and Medicine,State Key Laboratory of Radiation Medicine and Protection,Collaborative Innovation Center of Radiation Medicine of Jiangsu Higher Education Institutions,Soochow University,Suzhou 215123,China
  • Received:2021-02-19 Online:2021-08-10 Published:2021-08-05
  • Contact: MENG Xuanyu E-mail:xymeng@suda.edu.cn
  • Supported by:
    the National Natural Science Foundation of China(21503140)

Abstract:

Phosphatidylinositol 4,5-bisphosphate(PIP2) is a type of signaling phospholipid molecule distri-buted in the inner layer of the plasma membrane, which has regulatory effects on various transmembrane proteins such as potassium, sodium, chloride ion channels and transporters. TREK-1 is an important background potassium channel, which is regulated by various factors such as temperature, mechanical stretch, intracellular pH, etc. PIP2 activates the TREK-1 channel in a specific concentration range. Treatment of poly-lysine to inhibit the PIP2 in the inside-out patch clamp can cause the TREK-1 channel to close. Molecular docking and all-atom molecular dynamics simulation were used to explore the interaction of PIP2 on the two-pore-domain potassium channel TREK-1. Molecular docking calculations showed that PIP2 has two possible binding sites on the TREK-1 channel to activate the channel. Further use of molecular dynamics simulations and potential of mean force(PMF) calculations showed that the site located between the helix M4 and helix M1 is the preferential binding site for PIP2 to activate TREK-1. The simulation displayed the possible configuration of PIP2 bin-ding to TREK-1. The phosphate groups in inositol head of PIP2 form stable salt bridges with the basic residues K45 located on M1, and K304 and R311 located on M4; K304 and R311 have been verified by mutation experiments, which play an important role in the activation of TREK-1 by PIP2. In addition, a series of hydrophobic residues on the helix M1 play key roles in stabilizing the long fat chains of PIP2.

Key words: TREK-1 channel, Phosphatidylinositol 4, 5-bisphosphate(PIP2), Molecular docking, Molecular dynamics simulation, Potential of mean force(PMF)

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