Molecular Architecture Influences the Thermally Induced Aggregation Behavior of Elastin-like Polypeptides
Molecular Architecture Influences the Thermally Induced Aggregation Behavior of Elastin-like Polypeptides
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DOI：
10.1021/bm201031m
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发表时间：
2011-11-01
影响因子：
6.2
通讯作者：
Holland, Nolan B.
中科院分区：
文献类型：
--
作者：
Ghoorchian, Ali;Holland, Nolan B.
弹性蛋白样多肽是热响应聚合物，在转变温度以上表现出相分离。通过对三臂星形多肽、线性多肽及其混合物的溶液进行表征，研究了分子结构对类弹性蛋白多肽溶液的温度响应行为的影响。这些生物合成的多肽具有精确的长度和氨基酸序列。测量转变温度作为分子量和溶液浓度的函数，并与它们的线性对应物进行比较。与线性对应物一样，转变温度与对数浓度线性相关。使用数学关系将不同多肽长度的转变温度数据拟合到使用聚合物线圈体积的基于体积的浓度。该模型的结果表明，线性ELP在转变温度下处于随机卷曲构象，而三臂ELP处于紧凑的延伸卷曲构象，与不同的聚集途径一致。包含三聚体和线性构建体的解决方案具有两个转变温度，进一步支持不同的聚集行为。
Elastin-like polypeptides are thermally responsive polymers that exhibit phase separation above a transition temperature. The effect of molecular architecture on the temperature responsive behavior of elastin-like polypeptide solution's was investigated by characterization of solutions of three-armed star polypeptides, linear polypeptides, and their mixtures. These biosynthesized polypeptides have precise lengths and amino acid sequences. Transition temperatures were measured as a function of molecular weight and solution concentration and compared to their linear counterparts. Like their linear counterparts, the transition temperature is linearly related to log concentration. A mathematical relationship was used to fit the transition temperature data of different polypeptide lengths to a volume-based concentration using the polymer coil volume. The results of this model suggest that the linear ELP is in a random coil conformation at the transition temperature while the three-armed ELP is in a compact extended coil conformation, consistent with different pathways for aggregation. Solutions containing both trimer and linear constructs have two transition temperatures, further supporting differing aggregation behaviors.