Siderophores and mussel foot proteins: the role of catechol, cations, and metal coordination in surface adhesion

Abstract

Metal coordination, hydrogen bonding, redox reactions, and covalent crosslinking are seemingly disparate chemical and physicochemical processes that are all accomplished in natural materials by the catechol functional group. This review focuses on the reactivity of catechols in tris-2,3-dihydroxybenzoyl-containing microbial siderophores and synthetic analogs, as well as Dopa-(3,4-dihydroxyphenylalanine)-containing mussel foot proteins that adhere to surfaces in aqueous conditions.Mussel foot proteins with a high content of Dopa and cationic amino acids, Lys and Arg, adhere strongly to mica, an aluminosilicate mineral, in aqueous conditions. The siderophore cyclic trichrysobactin, tris-(2,3-dihydroxybenzoyl-D-Lys-L-Ser) and related synthetic analogs in which the tri-Ser macrolactone is replaced by Tren, tris-(2-aminoethyl)amine, also adheres strongly to mica. Variation in the nature of the catechol and cationic groups in synthetic analogs reveals a synergism between the cationic amino acid and the catechol, required for strong aqueous adhesion. Autoxidation and iron(III)-catalyzed oxidation of 2,3-dihydroxy and 3,4-dihydroxy catechols is also considered. These siderophore analogs provide a platform to understand catechol interactions and reactivity on surfaces, which may ultimately improve the design of synthetic materials that address diverse challenges in medicine, materials science, as well as other disciplines, in which surface adhesion in aqueous conditions is important.

The Chemistry behind Catechol‐Based Adhesion

“…Thefundamental knowledge regarding the role of iron in the adhesion properties of byssal threads [163] has fuelled the development of novel materials and applications,f or example,s urgical adhesives and orthopaedic cements, [164] versatile metal-phenolic platforms used to engineer nanomaterials and biointerfaces, [165] dendritic polymers as universal multifunctional coatings, [166] and novel hydrogel actuators inspired by the reversible mfp chemistry. [167] Ther eversibility of the DOPA-iron bond has also been used to fabricate self-healing hydrogels with stretching capacities ten times their original lengths.…”

Properties of temporary adhesion systems of marine and freshwater organisms

“…In recent decades, the research on adhesive secretions has mainly focused on marine, permanently attaching animals, such as mussels and barnacles (reviewed in Kamino, 2010;Maier and Butler, 2017;Waite, 2017). In contrast to the substantial advances in the understanding of permanent adhesives, the field of temporary adhesion is largely unexplored.…”

Die chemischen Grundlagen der Adhäsion von Catechol

“…Alternatively, higher pH values (similar to those found in seawater) favour catechol deprotonation and thus the formation of more iron-catechol bonds and a consequent remarkable increase in cohesion forces. All the fundamental knowledge regarding the role of iron in the adhesion properties of byssal threads [ 163 ] has fuelled the development of novel materials and applications, e.g., surgical adhesives and orthopaedic cements, [164] versatile metal-phenolic platforms used to engineer nanomaterials and biointerfaces, [165] dendritic polymers as universal multifunctional coatings [166] and novel hydrogel actuators inspired by the reversible mfp chemistry. [167] The reversibility of the DOPA-iron bond has also been used to fabricate self-healing hydrogels with stretching capacities ten times their original lengths.…”