Metal-mediated molecular self-healing in histidine-rich mussel peptides.
Mussels withstand high-energy wave impacts in rocky seashore habitats by fastening tightly to surfaces with tough and self-healing proteinaceous fibers called byssal threads. Thread mechanical behavior is believed to arise from reversibly breakable metal coordination cross-links embedded in histidine-rich protein domains (HRDs) in the principle load-bearing proteins comprising the fibrous thread core. In order to investigate HRD behavior at the molecular level, we have synthesized a histidine-rich peptide derived from mussel proteins (His5-bys) and studied its reversible adhesive self-interaction in the presence and absence of metal ions using PEG-based soft-colloidal probes (SCPs). Adhesion energies of greater than 0.3 mJ/m(2) were measured in the presence of metal ions, and the stiffness of the modified SCPs exhibited a 3-fold increase, whereas no adhesion was observed in the absence of metals. Raman spectroscopy confirmed the presence of metal-coordination via histidine residues by the peptide-supporting the role of His-metal complexes in the mechanical behavior of the byssus.
Departments of ‡Biomaterials and §Biomolecular Systems, Max Planck Institute of Colloids and Interfaces , 14424 Potsdam, Germany.
Stephan
S
Schmidt
Antje
A
Reinecke
Felix
F
Wojcik
Daniel
D
Pussak
Laura
L
Hartmann
Matthew James
MJ
Harrington
D000268:Adhesiveness; D000818:Animals; D049872:Bivalvia / Q000737:chemistry*; D003102:Colloids / Q000737:chemistry; D006639:Histidine / Q000737:chemistry*; D015394:Molecular Structure; D009532:Nickel / Q000737:chemistry*; D010316:Particle Size; D010455:Peptides / Q000138:chemical synthesis / Q000737:chemistry*; D011092:Polyethylene Glycols / Q000737:chemistry; D013499:Surface Properties
D003102:Colloids; D010455:Peptides; D011092:Polyethylene Glycols; D006639:Histidine; D009532:Nickel