Pointer-Keenan Caroline D, Lee Dong-Kuk, Hallok Kevin, Tan Anmin, Zand Robert, Ramamoorthy Ayyalusamy
Department of Chemistry, University of Michigan, Ann Arbor, MI 48109-1055, USA.
Chem Phys Lipids. 2004 Nov;132(1):47-54. doi: 10.1016/j.chemphyslip.2004.09.004.
Interaction of bovine myelin basic protein and its constituent charge isomers (C1-C3) with phospholipid bilayers was studied using solid-state NMR experiments on model membranes. 31P NMR experiments on multilamellar vesicles and mechanically aligned bilayers were used to measure the degree of protein-induced disorder in the lipid headgroup region while 2H NMR data provided the disorder caused by the protein in the hydrophobic core of the bilayers. Our results suggest that MBP and its charge isomers neither fragment nor significantly disrupt DMPC, POPC, POPC:POPG, and POPE bilayers. These results demonstrate that the MBP-induced fragmentation of POPC bilayers is due to the freeze-thaw cycles used in the preparation of multilamellar vesicles and not due to intrinsic protein-lipid interactions.
利用对模型膜进行的固态核磁共振实验，研究了牛髓鞘碱性蛋白及其组成电荷异构体（C1 - C3）与磷脂双层的相互作用。对多层囊泡和机械排列的双层膜进行的³¹P核磁共振实验，用于测量脂质头部区域蛋白质诱导的无序程度，而²H核磁共振数据则提供了蛋白质在双层膜疏水核心中引起的无序情况。我们的结果表明，髓鞘碱性蛋白及其电荷异构体既不会使二肉豆蔻酰磷脂酰胆碱（DMPC）、1-棕榈酰-2-油酰磷脂酰胆碱（POPC）、1-棕榈酰-2-油酰磷脂酰甘油（POPC:POPG）和1-棕榈酰-2-油酰磷脂酰乙醇胺（POPE）双层膜碎片化，也不会对其造成显著破坏。这些结果表明，髓鞘碱性蛋白诱导的1-棕榈酰-2-油酰磷脂酰胆碱双层膜碎片化是由于制备多层囊泡时使用的冻融循环，而非蛋白质与脂质的内在相互作用。
