Dietrich Undine, Krüger Peter, Gutberlet Thomas, Käs Josef A
Division of Soft Matter Physics, Faculty for Physics and Earth Sciences, University of Leipzig, Linnéstr. 5, D-04103 Leipzig, Germany.
Biochim Biophys Acta. 2009 Jul;1788(7):1474-81. doi: 10.1016/j.bbamem.2009.04.001. Epub 2009 Apr 9.
In this present work we have studied the effect of MARCKS (151-175) peptide on a mixed DPPC/PIP2 monolayer. By means of film balance, fluorescence microscopy, x-ray reflection/diffraction and neutron reflection measurements we detected changes in the lateral organization of the monolayer and changes in the perpendicular orientation of the PIP2 molecules depending on the presence of MARCKS (151-175) peptide in the subphase. In the mixed monolayer, the PIP2 molecules are distributed uniformly in the disordered phase of the monolayer, whereas the PI(4,5) groups elongate up to 10 A below the phosphodiester groups. This elongation forms the precondition for the electrostatic interaction of the MARCKS peptide with the PIP2 molecules. Due to the enrichment of PIP2 in the disordered phase, the interaction with the peptide occurs primarily in this phase, causing the PI(4,5) groups to tilt toward the monolayer interface.
在本研究中，我们研究了MARCKS（151 - 175）肽对混合的二棕榈酰磷脂酰胆碱/磷脂酰肌醇-4,5-二磷酸（DPPC/PIP2）单层膜的影响。通过膜天平、荧光显微镜、X射线反射/衍射和中子反射测量，我们检测到单层膜横向组织的变化以及取决于亚相中MARCKS（151 - 175）肽的存在与否的PIP2分子垂直取向的变化。在混合单层膜中，PIP2分子均匀分布在单层膜的无序相中，而磷脂酰肌醇-4,5-二磷酸（PI(4,5)）基团在磷酸二酯基团下方伸长至10埃。这种伸长形成了MARCKS肽与PIP2分子静电相互作用的前提条件。由于PIP2在无序相中的富集，与肽的相互作用主要发生在该相中，导致PI(4,5)基团向单层膜界面倾斜。
