Surface force measurements and simulations of mussel-derived peptide adhesives on wet organic surfaces

Zachary A Levine; Michael V Rapp; Wei Wei; Ryan Gotchy Mullen; Chun Wu; Gül H Zerze; Jeetain Mittal; J Herbert Waite; Jacob N Israelachvili; Joan-Emma Shea

doi:10.1073/pnas.1603065113

Surface force measurements and simulations of mussel-derived peptide adhesives on wet organic surfaces

Proc Natl Acad Sci U S A. 2016 Apr 19;113(16):4332-7. doi: 10.1073/pnas.1603065113. Epub 2016 Mar 28.

Authors

Affiliations

¹ Department of Physics, University of California, Santa Barbara, CA 93106; Department of Chemistry and Biochemistry, University of California, Santa Barbara, CA 93106;
² Department of Chemical Engineering, University of California, Santa Barbara, CA 93106;
³ Materials Research Laboratory, University of California, Santa Barbara, CA 93106;
⁴ Department of Chemistry and Biochemistry, Rowan University, Glassboro, NJ 08028;
⁵ Department of Chemical and Biomolecular Engineering, Lehigh University, Bethlehem, PA 18015;
⁶ Materials Research Laboratory, University of California, Santa Barbara, CA 93106; Department of Molecular, Cell and Developmental Biology, University of California, Santa Barbara, CA 93106.
⁷ Department of Chemical Engineering, University of California, Santa Barbara, CA 93106; Materials Research Laboratory, University of California, Santa Barbara, CA 93106; jacob@engineering.ucsb.edu shea@chem.ucsb.edu.
⁸ Department of Physics, University of California, Santa Barbara, CA 93106; Department of Chemistry and Biochemistry, University of California, Santa Barbara, CA 93106; jacob@engineering.ucsb.edu shea@chem.ucsb.edu.

Abstract

Translating sticky biological molecules-such as mussel foot proteins (MFPs)-into synthetic, cost-effective underwater adhesives with adjustable nano- and macroscale characteristics requires an intimate understanding of the glue's molecular interactions. To help facilitate the next generation of aqueous adhesives, we performed a combination of surface forces apparatus (SFA) measurements and replica-exchange molecular dynamics (REMD) simulations on a synthetic, easy to prepare, Dopa-containing peptide (MFP-3s peptide), which adheres to organic surfaces just as effectively as its wild-type protein analog. Experiments and simulations both show significant differences in peptide adsorption on CH3-terminated (hydrophobic) and OH-terminated (hydrophilic) self-assembled monolayers (SAMs), where adsorption is strongest on hydrophobic SAMs because of orientationally specific interactions with Dopa. Additional umbrella-sampling simulations yield free-energy profiles that quantitatively agree with SFA measurements and are used to extract the adhesive properties of individual amino acids within the context of MFP-3s peptide adhesion, revealing a delicate balance between van der Waals, hydrophobic, and electrostatic forces.

Keywords: molecular dynamics simulations; mussel foot proteins; protein folding; self-assembled monolayers; surface forces apparatus.

Publication types

Research Support, N.I.H., Extramural
Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

Adhesives / chemistry*
Animals
Bivalvia / chemistry*
Models, Chemical*
Peptides / chemistry*
Wettability

Substances

Adhesives
Peptides

Grants and funding

R01 DE018468/DE/NIDCR NIH HHS/United States