Comparison of adsorption behavior of two Mytilus edulis foot proteins on three surfaces

Abstract

The sea mussel Mytilus edulis fabricates a hold-fast (an adhesive plaque) from a proteinaceous mixture that it extrudes into a cavity formed by an organ called the ‘foot’. A family of four proteins in the mixture known as M. edulis foot proteins (Mefp 1–4) have been purified to homogeneity. Mefp-1 and 2 are the most well-characterized and most easily purified members of the Mefp family. They constitute about 5 and 25% of the content of the plaque, respectively. It has been proposed that Mefp-1 mediates bonding to the intended substratum while Mefp-2 serves more as a structural component. In order to provide data relevant to this hypothesis, the adsorption behavior of Mefp-1 and 2 was compared on three surfaces using attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR). Surfaces were germanium (Ge), polystyrene (PS) or poly(octadecyl)methacrylate (POMA). Polymer surfaces were prepared by spin casting onto the flat face of Ge trapezoidal internal reflection elements (IRE). Adsorption behavior was characterized by analyzing the kinetics of adsorption using a double exponential fit. The data indicate that the adsorption behavior of Mefp-1 and 2 is similar on the three surfaces both in terms of rate of adsorption and surface coverage attained over a short (<60 min) time period.