中国物理B ›› 2016, Vol. 25 ›› Issue (9): 90507-090507.doi: 10.1088/1674-1056/25/9/090507

• SPECIAL TOPIC—Physical research in liquid crystal • 上一篇    下一篇

Analysis of the induction of the myelin basic protein binding to the plasma membrane phospholipid monolayer

Lei Zhang(张蕾), Changchun Hao(郝长春), Ying Feng(冯盈), Feng Gao(高峰), Xiaolong Lu(逯晓龙), Junhua Li(李俊花), Runguang Sun(孙润广)   

  1. School of Physics and Information Technology, Shaanxi Normal University, Xi'an 710062, China
  • 收稿日期:2016-05-11 修回日期:2016-06-29 出版日期:2016-09-05 发布日期:2016-09-05
  • 通讯作者: Changchun Hao, Runguang Sun E-mail:haochangchun@snnu.edu.cn;sunrunguang@snnu.edu.cn
  • 基金资助:
    Project supported by the National Natural Science Foundation of China (Grant Nos. 21402114 and 11544009), the Natural Science Basic Research Plan in Shaanxi Province of China (Grant No. 2016JM2010), the Fundamental Research Funds for the Central Universities of China (Grant No. GK201604004), and the National University Science and Technology Innovation Project of China (Grant Nos. 201610718014 and cx16018).

Analysis of the induction of the myelin basic protein binding to the plasma membrane phospholipid monolayer

Lei Zhang(张蕾), Changchun Hao(郝长春), Ying Feng(冯盈), Feng Gao(高峰), Xiaolong Lu(逯晓龙), Junhua Li(李俊花), Runguang Sun(孙润广)   

  1. School of Physics and Information Technology, Shaanxi Normal University, Xi'an 710062, China
  • Received:2016-05-11 Revised:2016-06-29 Online:2016-09-05 Published:2016-09-05
  • Contact: Changchun Hao, Runguang Sun E-mail:haochangchun@snnu.edu.cn;sunrunguang@snnu.edu.cn
  • Supported by:
    Project supported by the National Natural Science Foundation of China (Grant Nos. 21402114 and 11544009), the Natural Science Basic Research Plan in Shaanxi Province of China (Grant No. 2016JM2010), the Fundamental Research Funds for the Central Universities of China (Grant No. GK201604004), and the National University Science and Technology Innovation Project of China (Grant Nos. 201610718014 and cx16018).

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摘要： Myelin basic protein (MBP) is an essential structure involved in the generation of central nervous system (CNS) myelin. Myelin shape has been described as liquid crystal structure of biological membrane. The interactions of MBP with monolayers of different lipid compositions are responsible for the multi-lamellar structure and stability of myelin. In this paper, we have designed MBP-incorporated model lipid monolayers and studied the phase behavior of MBP adsorbed on the plasma membrane at the air/water interface by thermodynamic method and atomic force microscopy (AFM). By analyzing the pressure-area (π-A) and pressure-time (π-T) isotherms, univariate linear regression equation was obtained. In addition, the elastic modulus, surface pressure increase, maximal insertion pressure, and synergy factor of monolayers were detected. These parameters can be used to modulate the monolayers binding of protein, and the results show that MBP has the strongest affinity for 1,2-dipalmitoyl-sn-glycero-3- phosphoserine (DPPS) monolayer, followed by DPPC/DPPS mixed and 1,2-dipalmitoyl-sn-glycero-3-phospho-choline (DPPC) monolayers via electrostatic and hydrophobic interactions. AFM images of DPPS and DPPC/DPPS mixed monolayers in the presence of MBP (5 nM) show a phase separation texture at the surface pressure of 20 mN/m and the incorporation of MBP put into the DPPC monolayers has exerted a significant effect on the domain structure. MBP is not an integral membrane protein but, due to its positive charge, interacts with the lipid head groups and stabilizes the membranes. The interaction between MBP and phospholipid membrane to determine the nervous system of the disease has a good biophysical significance and medical value.

关键词: myelin basic protein, liquid crystal monolayers, synergy factor, surface morphology

Abstract: Myelin basic protein (MBP) is an essential structure involved in the generation of central nervous system (CNS) myelin. Myelin shape has been described as liquid crystal structure of biological membrane. The interactions of MBP with monolayers of different lipid compositions are responsible for the multi-lamellar structure and stability of myelin. In this paper, we have designed MBP-incorporated model lipid monolayers and studied the phase behavior of MBP adsorbed on the plasma membrane at the air/water interface by thermodynamic method and atomic force microscopy (AFM). By analyzing the pressure-area (π-A) and pressure-time (π-T) isotherms, univariate linear regression equation was obtained. In addition, the elastic modulus, surface pressure increase, maximal insertion pressure, and synergy factor of monolayers were detected. These parameters can be used to modulate the monolayers binding of protein, and the results show that MBP has the strongest affinity for 1,2-dipalmitoyl-sn-glycero-3- phosphoserine (DPPS) monolayer, followed by DPPC/DPPS mixed and 1,2-dipalmitoyl-sn-glycero-3-phospho-choline (DPPC) monolayers via electrostatic and hydrophobic interactions. AFM images of DPPS and DPPC/DPPS mixed monolayers in the presence of MBP (5 nM) show a phase separation texture at the surface pressure of 20 mN/m and the incorporation of MBP put into the DPPC monolayers has exerted a significant effect on the domain structure. MBP is not an integral membrane protein but, due to its positive charge, interacts with the lipid head groups and stabilizes the membranes. The interaction between MBP and phospholipid membrane to determine the nervous system of the disease has a good biophysical significance and medical value.

Key words: myelin basic protein, liquid crystal monolayers, synergy factor, surface morphology

中图分类号:  (Thermodynamics)

  • 05.70.-a