Part I. Single molecule mechanical testing of elastomeric molecules using AFM. Part II. Genetically directed synthesis of a biomimetic adhesive protein.

摘要

In Part I of this work, the aim was to provide a more efficient method for measuring single molecular mechanical properties and subsequently employ that method to investigate the nanomechanical behavior of a synthetic polypeptide that mimics the elastomeric domains of native elastin. This process utilized the covalent attachment of the molecule at one end to a tip array, and at the other end to an AFM tipless cantilever via a streptavidin/biotin conjugate interaction. This strategy enabled replicate measurements on the same molecule, resulting in force-distance curves rich in information providing nanomechanical properties of merit for elasticity of single molecules of this important biomaterial. These parameters may be efficacious in tissue engineering and drug delivery systems as well as critical for the design of single molecules for use as bioactuators.; In Part II of this work, the goal was the design of periodic adhesive biomaterials from genetically directed synthesis of polypeptides. The biomimetic approach employed naturally occurring marine mussel adhesive protein as a design model. A mussel adhesive protein analogue was prepared through the implementation of a method for the synthesis and cloning of concatemeric genes as well as the amplification and cloning of the corresponding t RNA synthetase to ensure global incorporation of non-canonical amino acid residues. Bio-mimetic protein adhesives were synthesized and their composition and molar masses verified by analyses. The in vivo incorporation of the non-canonical amino acid residue, L-DOPA, was verified and the analyses suggest that this substitution was nearly complete.