Protein- and metal-dependent interactions of a prominent protein in mussel adhesive plaques.

TitleProtein- and metal-dependent interactions of a prominent protein in mussel adhesive plaques.
Publication TypeJournal Article
Year of Publication2010
AuthorsHwang, DSoo, Zeng, H, Masic, A, Harrington, MJ, Israelachvili, JN, Waite, JH
JournalJ Biol Chem
Date Published2010 Aug 13
KeywordsAmino Acid Sequence, Animals, Bivalvia, Calcium, Focal Adhesions, Iron, Models, Biological, Molecular Sequence Data, Proteins, Sequence Homology, Amino Acid, Spectrum Analysis, Raman

The adhesive plaques of Mytilus byssus are investigated increasingly to determine the molecular requirements for wet adhesion. Mfp-2 is the most abundant protein in the plaques, but little is known about its function. Analysis of Mfp-2 films using the surface forces apparatus detected no interaction between films or between a film and bare mica; however, addition of Ca(2+) and Fe(3+) induced significant reversible bridging (work of adhesion W(ad) approximately 0.3 mJ/m(2) to 2.2 mJ/m(2)) between two films at 0.35 m salinity. The strongest observed Fe(3+)-mediated bridging approaches the adhesion of oriented avidin-biotin complexes. Raman microscopy of plaque sections supports the co-localization of Mfp-2 and iron, which interact by forming bis- or tris-DOPA-iron complexes. Mfp-2 adhered strongly to Mfp-5, a DOPA-rich interfacial adhesive protein, but not to another interfacial protein, Mfp-3, which may in fact displace Mfp-2 from mica. In the presence of metal ions or Mfp-5, Mfp-2 adhesion was fully reversible. These results suggest that plaque cohesiveness depends on Mfp-2 complexation of metal ions, particularly Fe(3+) and also by Mfp-2 interaction with Mfp-5 at the plaque-substratum interface.

Alternate JournalJ. Biol. Chem.
PubMed ID20566644
PubMed Central IDPMC2919147
Grant ListDE018468 / DE / NIDCR NIH HHS / United States
R01 DE018468 / DE / NIDCR NIH HHS / United States
R01 DE018468-01A1 / DE / NIDCR NIH HHS / United States
R01 DE018468-02 / DE / NIDCR NIH HHS / United States