Salinas Dino G, De La Fuente Milton, Reyes Juan G
Facultad de Ciencias de la Salud, Universidad Diego Portales, Santiago, Chile.
Biophys J. 2005 Aug;89(2):885-94. doi: 10.1529/biophysj.104.057307. Epub 2005 May 13.
The static fluid mosaic model of biological membranes has been progressively complemented by a dynamic membrane model that includes phospholipid reordering in domains that are proposed to extend from nanometers to microns. Kinetic models for lipolytic enzymes have only been developed for homogeneous lipid phases. In this work, we develop a generalization of the well-known surface dilution kinetic theory to cases where, in a same lipid phase, both domain and nondomain phases coexist. Our model also allows understanding the changes in enzymatic activity due to a decrease of free substrate concentration when domains are induced by peptides. This lipid reordering and domain dynamics can affect the activity of lipolytic enzymes, and can provide a simple explanation for how basic peptides, with a strong direct interaction with acidic phospholipids (such as beta-amyloid peptide), may cause a complex modulation of the activities of many important enzymes in lipid signaling pathways.
生物膜的静态流体镶嵌模型已逐渐被动态膜模型所补充，该动态膜模型包括在从纳米到微米尺度延伸的区域中发生的磷脂重排。脂解酶的动力学模型仅针对均匀脂质相开发。在这项工作中，我们将著名的表面稀释动力学理论推广到同一脂质相中区域相和非区域相共存的情况。我们的模型还能够解释当肽诱导形成区域时，由于游离底物浓度降低而导致的酶活性变化。这种脂质重排和区域动态可以影响脂解酶的活性，并能为碱性肽（如β-淀粉样肽）与酸性磷脂具有强烈直接相互作用时如何对脂质信号通路中许多重要酶的活性产生复杂调节提供一个简单解释。
