Molecular Structure and Function Program, Research Institute, The Hospital for Sick Children, and Department of Biochemistry, University of Toronto, 555 University Avenue, Toronto, Ontario, Canada M5G1X8.
Biochemistry. 2010 Jul 13;49(27):5726-33. doi: 10.1021/bi100468v.
Elastin is the polymeric extracellular matrix protein responsible for the properties of extensibility and elastic recoil in tissues such as arterial blood vessels, lung parenchyma, and skin. Both tropoelastin (TE), the full-length monomeric form of elastin, and elastin-like polypeptides (ELPs), based on sequences and domain arrangements of TE, have the intrinsic ability to undergo organized self-assembly into network structures through a process of temperature-induced phase separation or coacervation. It has been suggested that this property plays a role in in vivo formation of the extracellular elastic matrix. In general, the temperature at which phase separation takes place has been taken as the measure of propensity for self-assembly. However, this phase separation is only the first step in a more complex, multistep process of network formation. We have previously shown that analysis of spectrophotometric data allows extraction of kinetic parameters describing both early (coacervation) and later (maturation) steps of the self-assembly process. Here, using a well-characterized ELP containing three hydrophobic domains flanking two cross-linking domains, we describe the effects of temperature, polypeptide concentration, and solution conditions on the kinetics of self-assembly, providing insights into possible mechanisms for the spontaneous organization of such ELPs into extended networks.
弹性蛋白是一种聚合细胞外基质蛋白，负责组织如动脉血管、肺实质和皮肤的伸展性和弹性回弹特性。原弹性蛋白（TE）全长的单体形式，以及基于 TE 序列和结构域排列的弹性蛋白样多肽（ELPs），都具有通过温度诱导的相分离或凝聚过程进行有组织的自组装成网络结构的内在能力。有人认为，这种特性在体内形成细胞外弹性基质中发挥作用。一般来说，发生相分离的温度被用作自组装倾向的衡量标准。然而，这种相分离只是网络形成更复杂的多步过程的第一步。我们之前已经表明，分光光度数据分析可以提取描述自组装过程早期（凝聚）和后期（成熟）阶段的动力学参数。在这里，我们使用一种经过良好表征的 ELP，其中包含三个疏水性结构域和两个交联结构域，描述了温度、多肽浓度和溶液条件对自组装动力学的影响，为这种 ELP 自发组织成延伸网络的可能机制提供了深入了解。
