Binding of peptides with basic and aromatic residues to bilayer membranes - Phenylalanine in the myristoylated alanine-rich C kinase substrate effector domain penetrates into the hydrophobic core of the bilayer
Binding of peptides with basic and aromatic residues to bilayer membranes - Phenylalanine in the myristoylated alanine-rich C kinase substrate effector domain penetrates into the hydrophobic core of the bilayer
复制标题
DOI：
10.1074/jbc.m301652200
复制
发表时间：
2003-06-13
影响因子：
4.8
通讯作者：
Smith, SO
中科院分区：
文献类型：
--
作者：
Zhang, WY;Crocker, E;Smith, SO
与膜相关蛋白如豆蔻酰化富含丙氨酸的C激酶底物（MARCKS）的带正电荷区域的静电相互作用可能在调节质膜中游离磷脂酰肌醇4，5-二磷酸（PI（4，5）P-2）的水平中起作用. MARCKS蛋白和对应于效应结构域（含有13个碱性残基和5个苯丙氨酸的非结构化区域）MARCKS-（151 - 175）的肽都以高亲和力在双层膜的平面中横向螯合多价脂质PI（4，5）P2。我们使用高分辨率魔角旋转NMR来确定MARCKS（151 - 175）在膜双层中的位置，这对于理解螯合机制是必要的。二维核Overhauser增强光谱NMR实验中交叉弛豫速率的测量表明MARCKS（151 - 175）的五个Phe环渗透到含有磷脂酰甘油或PI（4，5）P-2的磷脂酰胆碱双层的酰基链区域中.具体而言，我们观察到强烈的交叉之间的芳族质子的苯丙氨酸环和酰基链质子的脂质，即使是非常短的（50毫秒）的混合时间。Phe环的位置意味着肽中相邻的带正电荷的氨基酸接近带负电荷的脂质磷酸的水平。MARCKS肽在极性头部基团区域中的深位置应通过“图像电荷”机制增强其对PI（4，5）P2的静电螯合。此外，该位置对膜曲率和局部表面压力效应具有有趣的影响，并且可能与多种具有碱性芳香族簇的其他蛋白质有关，例如磷脂酶D、GAP 43、SCAMP 2和N-甲基- D-天冬氨酸受体.
Electrostatic interactions with positively charged regions of membrane- associated proteins such as myristoylated alanine- rich C kinase substrate ( MARCKS) may have a role in regulating the level of free phosphatidylinositol 4,5- bisphosphate ( PI( 4,5) P-2) in plasma membranes. Both the MARCKS protein and a peptide corresponding to the effector domain ( an unstructured region that contains 13 basic residues and 5 phenylalanines), MARCKS-( 151 - 175), laterally sequester the polyvalent lipid PI( 4,5) P2 in the plane of a bilayer membrane with high affinity. We used high resolution magic angle spinning NMR to establish the location of MARCKS( 151 - 175) in membrane bilayers, which is necessary to understand the sequestration mechanism. Measurements of cross- relaxation rates in two- dimensional nuclear Overhauser enhancement spectroscopy NMR experiments show that the five Phe rings of MARCKS( 151 - 175) penetrate into the acyl chain region of phosphatidylcholine bilayers containing phosphatidylglycerol or PI( 4,5) P-2. Specifically, we observed strong crosspeaks between the aromatic protons of the Phe rings and the acyl chain protons of the lipids, even for very short ( 50 ms) mixing times. The position of the Phe rings implies that the adjacent positively charged amino acids in the peptide are close to the level of the negatively charged lipid phosphates. The deep location of the MARCKS peptide in the polar head group region should enhance its electrostatic sequestration of PI( 4,5) P2 by an " image charge" mechanism. Moreover, this location has interesting implications for membrane curvature and local surface pressure effects and may be relevant to a wide variety of other proteins with basic- aromatic clusters, such as phospholipase D, GAP43, SCAMP2, and the N- methyl- D- aspartate receptor.