Electrostatic and nonpolar peptide-membrane interactions. Lipid binding and functional properties of somatostatin analogues of charge z = +1 to z = +3.
Electrostatic and nonpolar peptide-membrane interactions. Lipid binding and functional properties of somatostatin analogues of charge z = +1 to z = +3.
复制标题
静电和非极性肽膜相互作用。
DOI：
10.1021/bi00088a025
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发表时间：
1993
期刊：
影响因子：
2.9
通讯作者：
Christian Bruns
中科院分区：
文献类型：
--
作者：
Joachim Seelig;Simon Nebel;Peter Ganz;Christian Bruns
用滴定量热法研究了四种结构相关的生长抑素类似物（有效电荷+0.4 <或= <或= +3）与脂膜的相互作用，并与肽的功能活性进行了比较。表面活性测量提供了70或135 A2的平均横截面，表明环状分子在空气-水界面处取向，其环系统与表面平行（z = +3）或垂直（z = +1），或者根据表面密度（z = +2）在两个取向之间切换。肽与超声处理的脂质囊泡的非特异性结合是以-4至-7.5kcal/mol的Δ H驱动的。通过结合静电引力，通过Gouy-Chapman理论计算，与非极性相互作用的非特异性表面分配平衡，实现了一致的定量分析的结合等温线。阳离子肽的静电吸引力根据肽电荷而强烈变化。由于环肽的平环结构，它们的真实物理电荷在膜表面被感测到，并且没有观察到“电荷屏蔽”。肽与带负电荷的膜结合伴随着0.23-0.38 H+/肽的N-末端氨基的质子摄取。从理论预测的0.39 H+/肽的偏差可以解释由优先结合的非质子化的物种。的非极性相互作用，所描述的四种肽的表面分配系数，落入一个狭窄的范围K一致的50-230 M-1，而表观的整体结合常数为200和5000 M-1之间。（250字处删节）
The interaction of four structurally related somatostatin analogues (effective electric charge +0.4 < or = < or = +3) with lipid membranes was studied with titration calorimetry and was compared with the functional activity of the peptides. Surface activity measurements provided average cross-sections of 70 or 135 A2, indicating that the cyclic molecules orient at the air-water interface with their ring system either parallel (z = +3) or perpendicular (z = +1) to the surface or switching between the two orientations according to the surface density (z = +2). The nonspecific binding of the peptides to sonified lipid vesicles was enthalpy-driven with a delta H of -4 to -7.5 kcal/mol. A consistent quantitative analysis of the binding isotherms was achieved by combining electrostatic attractions, calculated via the Gouy-Chapman theory, with a nonspecific surface partition equilibrium for the nonpolar interactions. The electrostatic attraction of the cationic peptides varied strongly according to the peptide charge. Due to the flat ring structure of the cyclic peptides, their true physical charge was sensed at the membrane surface, and no "charge screening" was observed. Peptide binding to the negative charged membrane was accompanied by a proton-uptake of the N-terminal amino group of 0.23-0.38 H+/peptide. Deviations from the theoretical prediction of 0.39 H+/peptide can be explained by a preferential binding of the nonprotonated species. The nonpolar interactions, as described by the surface partition coefficients of the four peptides, fell into a narrow range of K congruent to 50-230 M-1 whereas the apparent overall binding constants were between 200 and 5000 M-1.(ABSTRACT TRUNCATED AT 250 WORDS)
影响因子：
2.9
作者：
Marian Mosior;Stuart McLaughlin
通讯作者：
Marian Mosior;Stuart McLaughlin
影响因子：
2.9
作者：
MORIN, PE;FREIRE, E
通讯作者：
FREIRE, E
影响因子：
2.9
作者：
WISEMAN, T;WILLISTON, S;LIN, LN
通讯作者：
LIN, LN