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

Paper BI-TuP3
Adsorption Studies of Barnacle Cement Proteins from Balanus Improvisus

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

Session: Poster Session
Presenter: K. Mjorn, Goteborg University, Sweden
Authors: K. Mjorn, Goteborg University, Sweden
F. Hook, Goteborg University, Sweden
H. Elwing, Goteborg University, Sweden
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Marine specimens such as barnacles and mussels anchor themselves to solid surfaces with biological glues that are curable under water. The glue used by barnacles is called cement, which is a clear proteinous liquid. When a barnacle is dislodged from a surface under certain conditions, such cement is secreted. The adsorption of fresh cement from the barnacle Balanus improvisus without prior purification has been studied on an electrically inert non-polar methylterminated thiolated gold surface and polar gold surface by a combined use of Surface Plasmon Resonance (SPR) technique and an extended version of Quartz Crystal Microbalance (QCM-D) technique. With SPR, which is an optical surface sensitive method, we can determine the adsorbed amount of protein at the surface due to the difference in refractive index between water and the protein. With QCM-D, an acoustic method, we can determine the degree of bound water in the protein layer and the structural flexibility of the proteins. The adsorbed mass was almost twice as great for the hydrophilic gold surface compared to the mass adsorbed on the hydrophobic surface showed with SPR. The amount coupled water did not differ in a great extent between the two surfaces. This indicates that the flexibility and the amount adsorbed water did not vary much with the chemistry of the surface, in contrast to the mussel adhesive protein, Mepf-1, showed by C. Fant et al.@footnote 1@ The behavior of the cement monolayer could then be followed with these two methods when the buffer conditions where changed, e.g. ionic strength and pH. The influence of this was also followed with 2D SDS-PAGE, where the separation of fresh cement was compared to treated cement. How and at which circumstances the cement is cured is under investigation. @FootnoteText@ @footnote 1@C. Fant, K. Mjorn, H. Elwing and F. Hook, Adsorption behavior and enzymatic induced cross-linking of mussel adhesive protein (submitted).