AVS 46th International Symposium
    Biomaterial Interfaces Group Tuesday Sessions
       Session BI-TuP

Paper BI-TuP6
Adsorption Behaviour and Enzymatic Induced Cross-linking of the Mussel Adhesive Protein, Mefp-1

Tuesday, October 26, 1999, 5:30 pm, Room 4C

Session: Poster Session
Presenter: C. Fant, Goteborg University, Sweden
Authors: C. Fant, Goteborg University, Sweden
H. Elwing, Goteborg University, Sweden
F. Hook, Goteborg University, Sweden
Correspondent: Click to Email
The blue mussel produces a family of 3, 4-dihydroxyphenylalanine (DOPA) containing proteins that allow the organisms to attach themselves to solid surfaces with high adhesive strength. We have studied the adsorption behaviour of the mussel adhesive protein, mefp-1, to a non-polar CH@sub 3@-terminated thiolated gold surface and to a polar silicone dioxide (SiO@sub 2@) surface. Cross-linking of these monolayers was induced by catechol oxidase, which catalyses the transformation of DOPA to a highly reactive o-quinone participating in cross-linking. The adsorption and the cross-linking of mefp-1 was studied with respect to changes in the mass and viscoelastic properties of the protein adlayer. This has been possible by combined use of the Surface Plasmon Resonance (SPR) and an extended version of the Quarts Crystal Micro Balance (QCM-D@super TM@). The SPR response are proportional to the adsorbed mass (m). QCM-D measures change in mass uptake as a change in frequency (f) of a piezo electric quartz crystal. The change in frequency is proportional to the adsorbed mass including trapped water. In addition, the QCM-D technique allows simultaneous measurement of the energy dissipation (D) related to the rigidity/viscoelasticity of the adlayer. The results suggest that the protein layer formed on the polar surface is rigidly attached. In contrast, the layer formed on the non-polar surface is flexible, and it contains a large amount of bound water. Upon cross-linking, the dissipation decreased more on the non-polar surface compared to the hydrophilic surface. This demonstrates that the combination of these techniques provides unique information with respect to rigidity and water content of the adsorbed protein. The combination of these two techniques also make it possible to study the cross-linking of mefp-1, which is important knowledge for the development of a medical glue.