A mussel-derived one component adhesive coacervate.
Marine organisms process and deliver many of their underwater coatings and adhesives as complex fluids. In marine mussels one such fluid, secreted during the formation of adhesive plaques, consists of a concentrated colloidal suspension of a mussel foot protein (mfp) known as Mfp-3S. The results of this study suggest that Mfp-3S becomes a complex fluid by a liquid-liquid phase separation from equilibrium solution at a pH and ionic strength reminiscent of the conditions created by the mussel foot during plaque formation. The pH dependence of phase separation and its sensitivity indicate that inter-/intra-molecular electrostatic interactions are partially responsible for driving the phase separation. Hydrophobic interactions between the non- polar Mfp-3S proteins provide another important driving force for coacervation. As complex coacervation typically results from charge-charge interactions between polyanions and polycations, Mfp-3S is thus unique in being the only known protein that coacervates with itself. The Mfp-3S coacervate was shown to have an effective interfacial energy of ⩽1mJm(-2), which explains its tendency to spread over or engulf most surfaces. Of particular interest to biomedical applications is the extremely high adsorption capacity of coacervated Mfp-3S on hydroxyapatite.
Materials Research Laboratory, University of California, Santa Barbara, CA 93106, USA.
Wei
W
Wei
Biomolecular Science and Engineering Graduate Program, University of California, Santa Barbara, CA 93106, USA.
Yerpeng
Y
Tan
Department of Molecular, Cell and Development Biology, University of California, Santa Barbara, CA 93106, USA.
Nadine R
NR
Martinez Rodriguez
Department of Chemical Engineering, University of California, Santa Barbara, CA 93106, USA.
Jing
J
Yu
Materials Research Laboratory, University of California, Santa Barbara, CA 93106, USA; Department of Chemical Engineering, University of California, Santa Barbara, CA 93106, USA. Electronic address: jacob@engineering.ucsb.edu.
Jacob N
JN
Israelachvili
Materials Research Laboratory, University of California, Santa Barbara, CA 93106, USA; Biomolecular Science and Engineering Graduate Program, University of California, Santa Barbara, CA 93106, USA; Department of Molecular, Cell and Development Biology, University of California, Santa Barbara, CA 93106, USA. Electronic address: herbert.waite@lifesci.ucsb.edu.
J Herbert
JH
Waite
D000268:Adhesiveness / Q000187:drug effects; D000327:Adsorption; D000595:Amino Acid Sequence; D000818:Animals; D049872:Bivalvia / Q000737:chemistry*; D002021:Buffers; D017886:Durapatite / Q000494:pharmacology; D006863:Hydrogen-Ion Concentration; D008969:Molecular Sequence Data; D009391:Nephelometry and Turbidimetry; D009994:Osmolar Concentration; D011506:Proteins / Q000737:chemistry / Q000494:pharmacology*; D058525:Quartz Crystal Microbalance Techniques; D013057:Spectrum Analysis; D013696:Temperature; D013997:Time Factors; D017155:Wettability
D002021:Buffers; D011506:Proteins; C037403:adhesive protein, mussel; D017886:Durapatite
Biological wet adhesion; Coacervate; Hydrophobicity; Hydroxyapatite; Interfacial energy; Mussel foot protein