用粗粒化分子动力学方法研究蜂毒素与磷脂双分子层的相互作用

Interactions of Melittin With Phospholipid Bilayers by Coarse-grained Molecular Dynamics

为了了解蜂毒素的生物活性机理,采用粗粒化分子动力学模拟方法研究了蜂毒素在水环境中的性质以及与多种磷脂双分子层膜的相互作用.结果表明:无论是在水环境还是在磷脂双分子层中,蜂毒素都能形成聚集体.在每个聚集体中,蜂毒素分子之间的相对位置不断变化,会在蜂毒素分子之间形成无特定形状的空隙,从而在膜内产生暂时的孔洞或者跨膜通道.蜂毒素分子的N端和C端带正电荷的残基与磷脂膜带负电荷的磷脂头之间的静电相互作用是蜂毒素发挥功能的关键因素.

To understand the mechanism of biological activity of melittin,the behaviors of melittin in aqueous environment and its interaction with a variety of phospholipid bilayer membranes were studied by coarse grained molecular dynamics method. Results show that the melittin molecules can form multimer both in the aqueous environment and in the phospholipid bilayer. In each multimer,the relative positions between the melittin monomers are constantly changing and voids with no specific shapes may form between monomers to create transient pores or transmembrane channels in the membrane. The electrostatic interactions between the N-terminal and C-terminal positively charged residues of melittin molecules and the negatively charged phospholipid heads of phospholipid membrane play a key role in the biological function of melittin.