Spring mechanics of alpha-helical polypeptide.
To design protein- and polymer-based micro-machineries, it is important to understand the mechanical properties of basic structural elements such as the alpha-helix of polypeptides. We employed the force measurement mode of an atomic force microscope (AFM) to investigate the spring mechanics of poly-L-glutamic acid (PGA) in its helical and randomly coiled states. After covalently anchoring the polypeptide between a silicon substrate and an AFM tip, the force required to stretch the polymer was measured. The results indicated that PGA in its helical conformation could be stretched almost fully with a continuous increase in the stretching force, suggesting that it can be used as a reliable coil-spring in the future design of spring-loaded molecular machineries.
Idiris
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Laboratory of Biodynamics, Faculty of Bioscience and Biotechnology, Tokyo Institute of Technology, 4259 Nagatsuta, Midori-ku, Yokohama 226-8501, Japan.
Alam
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Ikai
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D001696:Biomechanical Phenomena; D002942:Circular Dichroism; D018625:Microscopy, Atomic Force; D008958:Models, Molecular; D010455:Peptides / Q000737:chemistry*; D011099:Polyglutamic Acid / Q000737:chemistry*; D017433:Protein Structure, Secondary
D010455:Peptides; D011099:Polyglutamic Acid