title: The staying power of adhesion-associated antioxidant activity in Mytilus californianus.
abstract: The California mussel, Mytilus californianus, adheres in the highly oxidizing intertidal zone with a fibrous holdfast called the byssus using 3, 4-dihydroxyphenyl-l-alanine (DOPA)-containing adhesive proteins. DOPA is susceptible to oxidation in seawater and, upon oxidation, loses adhesion. Successful mussel adhesion thus depends critically on controlling oxidation and reduction. To explore how mussels regulate redox during their functional adhesive lifetime, we tracked extractable protein concentration, DOPA content and antioxidant activity in byssal plaques over time. In seawater, DOPA content and antioxidant activity in the byssus persisted much longer than expected-50% of extractable DOPA and 30% of extractable antioxidant activity remained after 20 days. Antioxidant activity was located at the plaque-substrate interface, demonstrating that antioxidant activity keeps DOPA reduced for durable and dynamic adhesion. We also correlated antioxidant activity to cysteine and DOPA side chains of mussel foot proteins (mfps), suggesting that mussels use both cysteine and DOPA redox reservoirs for controlling interfacial chemistry. These data are discussed in the context of the biomaterial structure and properties of the marine mussel byssus.
authors.affiliation: Biomolecular Science and Engineering, University of California, Santa Barbara, 93106-9611, USA.
authors.forename: Dusty R
authors.identifier: http://orcid.org/0000-0002-2376-4543
authors.initials: DR
authors.lastname: Miller
authors.affiliation: College of Creative Studies, Chemistry and Biochemistry, University of California, Santa Barbara, 93106-6110, USA.
authors.forename: Jamie E
authors.initials: JE
authors.lastname: Spahn
authors.affiliation: Department of Molecular, Cellular, and Developmental Biology, University of California, Santa Barbara, 93106-9625, USA waite@lifesci.ucsb.edu.
authors.forename: J Herbert
authors.initials: JH
authors.lastname: Waite
mesh_terms: D000268:Adhesiveness; D000818:Animals; D000975:Antioxidants / Q000737:chemistry*; D001672:Biocompatible Materials / Q000737:chemistry; D001713:Biphenyl Compounds / Q000737:chemistry; D003545:Cysteine / Q000737:chemistry; D004295:Dihydroxyphenylalanine / Q000737:chemistry; D049878:Mytilus / Q000737:chemistry*; D010084:Oxidation-Reduction; D010100:Oxygen / Q000737:chemistry; D010851:Picrates / Q000737:chemistry; D011485:Protein Binding; D011506:Proteins / Q000737:chemistry*; D012623:Seawater
chemical_list: D000975:Antioxidants; D001672:Biocompatible Materials; D001713:Biphenyl Compounds; D010851:Picrates; D011506:Proteins; C037403:adhesive protein, mussel; D004295:Dihydroxyphenylalanine; C004931:1,1-diphenyl-2-picrylhydrazyl; D003545:Cysteine; D010100:Oxygen
keywords: antioxidant activity; mussels; redox