Title | Boronate complex formation with Dopa containing mussel adhesive protein retards ph-induced oxidation and enables adhesion to mica. |
Publication Type | Journal Article |
Year of Publication | 2014 |
Authors | Kan, Y, Danner, EW, Israelachvili, JN, Chen, Y, Waite, JH |
Journal | PLoS One |
Volume | 9 |
Issue | 10 |
Pagination | e108869 |
Date Published | 2014 |
ISSN | 1932-6203 |
Keywords | Adhesives, Aluminum Silicates, Animals, Boronic Acids, Dihydroxyphenylalanine, Mollusca, Proteins |
Abstract | The biochemistry of mussel adhesion has inspired the design of surface primers, adhesives, coatings and gels for technological applications. These mussel-inspired systems often focus on incorporating the amino acid 3,4-dihydroxyphenyl-L-alanine (Dopa) or a catecholic analog into a polymer. Unfortunately, effective use of Dopa is compromised by its susceptibility to auto-oxidation at neutral pH. Oxidation can lead to loss of adhesive function and undesired covalent cross-linking. Mussel foot protein 5 (Mfp-5), which contains ∼ 30 mole % Dopa, is a superb adhesive under reducing conditions but becomes nonadhesive after pH-induced oxidation. Here we report that the bidentate complexation of borate by Dopa to form a catecholato-boronate can be exploited to retard oxidation. Although exposure of Mfp-5 to neutral pH typically oxidizes Dopa, resulting in a>95% decrease in adhesion, inclusion of borate retards oxidation at the same pH. Remarkably, this Dopa-boronate complex dissociates upon contact with mica to allow for a reversible Dopa-mediated adhesion. The borate protection strategy allows for Dopa redox stability and maintained adhesive function in an otherwise oxidizing environment. |
DOI | 10.1371/journal.pone.0108869 |
Alternate Journal | PLoS ONE |
PubMed ID | 25303409 |
PubMed Central ID | PMC4193769 |
Grant List | R01 DE018468 / DE / NIDCR NIH HHS / United States R01 DE018468 / DE / NIDCR NIH HHS / United States |