A Genetically Engineered Protein Responsive to Multiple Stimuli

摘要

Stimuli-responsive materials, including polymers, biopolymers, conjugates, and hydrogels, have emerged as an important class of materials for both fundamental study and applied research in many fields of science, including biology and medicine. At present these materials are prepared from a limited number of synthetic polymers, biopolymers, and biomimetic polymers. Protein engineering approaches to biomaterials design offer powerful strategies to overcome challenges and provide new opportunities in the design and rapid development of responsive biomaterials. Consequently, there is a significant paradigm shift in the design concept for new elastic biomaterials, from a synthesis-based approach to the utilization of dynamic structural motifs derived from extracellular matrix proteins. Responsive properties of the highly elastic protein elastin and elastin-mimetic proteins (EMPs) that exhibit tunable lower critical solution temperatures (LCST) have stimulated development of novel protein-based biomaterials.The sol-gel transition of gelatin that exhibits responsive upper critical solution temperature (UCST) behavior has also been of significant importance in the food and pharmaceutical industries. Green fluorescent protein (GFP) and genetically engineered GFP mutants that demonstrate tunable photophysical properties have revolutionized cell culture, biological assay, and targeted sensing. Recently, dual-phase behavior (DPB, the occurrence of both UCST and LCST) in proteins was predicted by Li et al. using molecular modeling. Herein we report for the first time the unique dual phase transitions and pH-responsive photophysical properties of the resilin mimetic elastic protein ree1-resilin.