Pandit Sagar A, Berkowitz Max L
Department of Chemistry, University of North Carolina, Chapel Hill, North Carolina 27599, USA.
Biophys J. 2002 Apr;82(4):1818-27. doi: 10.1016/S0006-3495(02)75532-X.
We performed a molecular dynamics simulation of dipalmitoylphosphatidylserine (DPPS) bilayer with Na+ counterions. We found that hydrogen bonding between the NH group and the phosphate group leads to a reduction in the area per headgroup when compared to the area in dipalmitoylphosphatidylcholine bilayer. The Na+ ions bind to the oxygen in the carboxyl group of serine, thus giving rise to a dipolar bilayer similar to dipalmitoylphosphatidylethanolamine bilayer. The results of the simulation show that counterions play a crucial role in determining the structural and electrostatic properties of DPPS bilayer.
我们对含有Na⁺抗衡离子的二棕榈酰磷脂酰丝氨酸（DPPS）双层进行了分子动力学模拟。我们发现，与二棕榈酰磷脂酰胆碱双层中的面积相比，NH基团与磷酸基团之间的氢键导致每个头基的面积减小。Na⁺离子与丝氨酸羧基中的氧结合，从而形成类似于二棕榈酰磷脂酰乙醇胺双层的偶极双层。模拟结果表明，抗衡离子在决定DPPS双层的结构和静电性质方面起着关键作用。
