Polyprotein of GB1 is an ideal artificial elastomeric protein

• Published in: Nature materials Vol. 6; no. 2; pp. 109 - 114
• Main Authors: Cao, Yi, Li, Hongbin
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 01.02.2007; Nature Publishing Group
• Subjects: Adhesion; Biomaterials; Biomimetic Materials - chemistry; Cell adhesion & migration; Chemistry and Materials Science; Condensed Matter Physics; Elastomers - chemistry; Fatigue; Kinetics; letter; Materials Science; Microscopy; Molecular biology; Nanotechnology; Optical and Electronic Materials; Polyproteins - chemical synthesis; Polyproteins - chemistry; Protein Engineering - methods; Protein Folding; Proteins; Working conditions
• ISSN: 1476-1122; 1476-4660
• DOI: 10.1038/nmat1825

Naturally occurring elastomeric proteins function as molecular springs in their biological settings and show mechanical properties that underlie the elasticity of natural adhesives 1 , cell adhesion proteins 2 and muscle proteins 3 . Constantly subject to repeated stretching–relaxation cycles, many elastomeric proteins demonstrate remarkable consistency and reliability in their mechanical performance 3 , 4 . Such properties had hitherto been observed only in naturally evolved elastomeric proteins. Here we use single-molecule atomic force microscopy techniques to demonstrate that an artificial polyprotein made of tandem repeats of non-mechanical protein GB1 has mechanical properties that are comparable or superior to those of known elastomeric proteins. In addition to its mechanical stability 5 , we show that GB1 polyprotein shows a unique combination of mechanical features, including the fastest folding kinetics measured so far for a tethered protein, high folding fidelity, low mechanical fatigue during repeated stretching–relaxation cycles and ability to fold against residual forces. These fine features make GB1 polyprotein an ideal artificial protein-based molecular spring that could function in a challenging working environment requiring repeated stretching–relaxation. This study represents a key step towards engineering artificial molecular springs with tailored nanomechanical properties for bottom-up construction of new devices and materials 6 .