Cao Yi, Li Hongbin
Nat Nanotechnol. 2008 Aug;3(8):512-6. doi: 10.1038/nnano.2008.168. Epub 2008 Jun 29.
Elastomeric proteins are molecular springs that confer excellent mechanical properties to many biological tissues and biomaterials. Depending on the role performed by the tissue or biomaterial, elastomeric proteins can behave as molecular springs or shock absorbers. Here we combine single-molecule atomic force microscopy and protein engineering techniques to create elastomeric proteins that can switch between two distinct types of mechanical behaviour in response to the binding of a molecular regulator. The proteins are mechanically labile by design and behave as entropic springs with an elasticity that is governed by their configurational entropy. However, when a molecular regulator binds to the protein, it switches into a mechanically stable state and can act as a shock absorber. These engineered proteins effectively mimic and combine the two extreme forms of elastic behaviour found in natural elastomeric proteins, and thus represent a new type of smart nanomaterial that will find potential applications in nanomechanics and material sciences.
弹性蛋白是赋予许多生物组织和生物材料优异机械性能的分子弹簧。根据组织或生物材料所发挥的作用，弹性蛋白可表现为分子弹簧或减震器。在此，我们结合单分子原子力显微镜和蛋白质工程技术，创造出能响应分子调节剂的结合而在两种不同机械行为之间切换的弹性蛋白。这些蛋白质经设计在机械性能上不稳定，表现为熵弹簧，其弹性由构象熵决定。然而，当分子调节剂与蛋白质结合时，它会转变为机械稳定状态并可充当减震器。这些工程蛋白有效地模拟并结合了天然弹性蛋白中发现的两种极端弹性行为形式，因此代表了一种新型智能纳米材料，将在纳米力学和材料科学中找到潜在应用。
