Morphological transformations in a dually thermoresponsive coil-rod-coil bioconjugate.
Morphological transformations in a dually thermoresponsive coil-rod-coil bioconjugate.
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DOI：
10.1039/c2sm07025a
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发表时间：
2012-04-14
期刊：
影响因子：
3.4
通讯作者：
Kiick KL
中科院分区：
文献类型：
--
作者：
Krishna OD;Wiss KT;Luo T;Pochan DJ;Theato P;Kiick KL
我们报道了一种温度响应性的三嵌段生物杂化共轭化合物在水条件下的构象和组装行为。该三嵌段由聚二甘醇甲基醚甲基丙烯酸酯(PDEGMEMA)组成，该聚乙二醇甲醚甲基丙烯酸酯(PDEGMEMA)连接到形成胶原蛋白样肽的三螺旋末端。圆二色谱(CD)实验证实了胶原肽中间嵌段在杂化偶合物中以三螺旋形式组装的能力。在LcST(~35°C)以上，热响应性PDEGMEMA聚合物在多肽结构域末端的坍塌导致多肽结构域对热变性的构象稳定性增加。冷却后，杂化偶合物中的多肽结构域仍观察到动力学构象折叠行为。静态光散射(SLS)实验表明，当溶液温度升高到LCST以上时，会形成超分子结构。散射强度随温度的升高而增大，在75℃时减小。低温扫描电子显微镜和常规透射电子显微镜表明，在65℃以下，随着温度的升高，可形成尺寸增大的球形聚集体，并在75℃时观察到形态向纤维的转变。三嵌段杂化中肽和聚合物嵌段的双重热响应行为对于观察到的构象和组装行为是协同作用的。
We report the conformational and assembly behavior of a thermoresponsive triblock biohybrid conjugate under aqueous conditions. The triblock comprises of poly(diethylene glycol methyl ether methacrylate) (PDEGMEMA) conjugated to the ends of a triple-helix forming collagen-like peptide. The circular dichroism (CD) experiment confirms the ability of the collagen-like peptide middle block to assemble as a triple helix in the hybrid conjugate. Above the LCST (~35 °C), the collapse of the thermoresponsive PDEGMEMA polymer at the ends of the peptide domain resulted in a concomitant increase in the conformational stability of the peptide domain towards thermal denaturation. Upon cooling back, the kinetic conformational refolding behavior was still observed for the peptide domain in the hybrid conjugate. Static light scattering (SLS) experiments suggested the formation of supramolecular structures upon increasing solution temperatures to above the LCST. The scattering intensity increased with increasing temperature, until at 75 °C then it was found to decrease. Cryogenic scanning electron microscopy and regular transmission electron microscopy suggested the formation of spherical aggregates that increased in size with increasing temperature up to 65 °C and a morphological transformation into fibrils was also observed at 75 °C. The synergistic effect of dual thermoresponsive behavior from the peptide and the polymer block in the triblock hybrid is suggested for the observed conformational and assembly behaviors.