Wang C, Stewart R J, Kopecek J
Department of Bioengineering, University of Utah, Salt Lake City 84112, USA.
Nature. 1999 Feb 4;397(6718):417-20. doi: 10.1038/17092.
Stimuli-sensitive polymer hydrogels, which swell or shrink in response to changes in the environmental conditions, have been extensively investigated and used as 'smart' biomaterials and drug-delivery systems. Most of these responsive hydrogels are prepared from a limited number of synthetic polymers and their derivatives, such as copolymers of (meth)acrylic acid, acrylamide and N-isopropyl acrylamide. Water-soluble synthetic polymers have also been crosslinked with molecules of biological origin, such as oligopeptides and oligodeoxyribonucleotides, or with intact native proteins. Very often there are several factors influencing the relationship between structure and properties in these systems, making it difficult to engineer hydrogels with specified responses to particular stimuli. Here we report a hybrid hydrogel system assembled from water-soluble synthetic polymers and a well-defined protein-folding motif, the coiled coil. These hydrogels undergo temperature-induced collapse owing to the cooperative conformational transition of the coiled-coil protein domain. This system shows that well-characterized water-soluble synthetic polymers can be combined with well-defined folding motifs of proteins in hydrogels with engineered volume-change properties.
对环境条件变化产生膨胀或收缩响应的刺激敏感型聚合物水凝胶，已得到广泛研究，并被用作“智能”生物材料和药物递送系统。这些响应性水凝胶大多由有限数量的合成聚合物及其衍生物制备而成，比如（甲基）丙烯酸、丙烯酰胺和N-异丙基丙烯酰胺的共聚物。水溶性合成聚合物也已与生物来源的分子交联，如寡肽和寡脱氧核糖核苷酸，或与完整的天然蛋白质交联。在这些体系中，通常有几个因素影响结构与性能之间的关系，这使得设计对特定刺激具有特定响应的水凝胶变得困难。在此，我们报道了一种由水溶性合成聚合物和明确的蛋白质折叠基序——卷曲螺旋组装而成的混合水凝胶体系。由于卷曲螺旋蛋白结构域的协同构象转变，这些水凝胶会发生温度诱导的塌陷。该体系表明，特征明确的水溶性合成聚合物可以与水凝胶中明确的蛋白质折叠基序相结合，从而具备工程化的体积变化特性。
