Adhesion mechanism in a DOPA-deficient foot protein from green mussels().

TitleAdhesion mechanism in a DOPA-deficient foot protein from green mussels().
Publication TypeJournal Article
Year of Publication2012
AuthorsHwang, DSoo, Zeng, H, Lu, Q, Israelachvili, JN, Waite, JH
JournalSoft Matter
Date Published2012

The holdfast or byssus of Asian green mussels, Perna viridis, contains a foot protein, pvfp-1, that differs in two respects from all other known adhesive mussel foot proteins (mfp): (1) instead of the hallmark L-3,4-dihydroxyphenylalanine (DOPA) residues in mfp-1, for example, pvfp-1 contains C(2)-mannosyl-7-hydroxytryptophan (Man7OHTrp). (2) In addition, pvfp-1 chains are not monomeric like mfp-1 but trimerized by collagen and coiled-coil domains near the carboxy terminus after a typical domain of tandemly repeated decapeptides. Here, the contribution of these peculiarities to adhesion was examined using a surface forces apparatus (SFA). Unlike previously studied mfp-1s, pvfp-1 showed significant adhesion to mica and, in symmetric pvfp-1 films, substantial cohesive interactions were present at pH 5.5. The role of Man7OHTrp in adhesion is not clear, and a DOPA-like role for Man7OHTrp in metal complexation (e.g., Cu(2+), Fe(3+)) was not observed. Instead, cation-π interactions with low desolvation penalty between Man7OHTrp and lysyl side chains and conformational changes (raveling and unraveling of collagen helix and coiled-coil domains) are the best explanations for the strong adhesion between pvfp-1 monomolecular films. The strong adhesion mechanism induced by cation-π interactions and conformational changes in pvfp-1 provides new insights for the development of biomimetic underwater adhesives.

Alternate JournalSoft Matter
PubMed ID23105946
PubMed Central IDPMC3482130
Grant ListR01 DE018468 / DE / NIDCR NIH HHS / United States