pH-dependent cross-linking of catechols through oxidation via Fe3+and potential implications for mussel adhesion

• DOI: 10.1039/c4ra03178d
• Publication Date: 2014-05-28T08:35:10Z
• Authors: Dominic E. Fullen...; Devin G. Barrett; Dusty R. Miller; Josh W. Kurutz; Phillip B. Messer...
• Keywords: Byssus; Catechol

The mussel byssus is a remarkable attachment structure that formed by injection molding and rapid in-situ hardening of concentrated solutions proteins enriched in the catecholic amino acid 3,4-dihydroxy-L-phenylalanine (DOPA). Fe3+, found high concentrations byssus, has been speculated to participate redox reactions with DOPA lead protein polymerization, however direct evidence support this hypothesis lacking. Using small molecule catechols, DOPA-containing peptides, native foot proteins, we report first observation catechol oxidation polymerization accompanied reduction Fe3+ Fe2+. In case catechol, identified two dominant dimer species characterized their connectivities nuclear magnetic resonance (NMR), C6-C6 C5-C6 linked as major minor products, respectively. For peptide, studied pH dependence reaction demonstrated occurs readily at low pH, but increasingly diminished favor metal-catechol coordination interactions higher pH. Finally, demonstrate can induce cross-links byssal mefp-1 mcfp-1 acidic Based on these findings, discuss potential implications chemistry adhesion.