Use of attenuated total internal reflection fourier transform infrared spectroscopy to investigate interactions between mytilus edulis foot proteins at a surface

Abstract

Sea mussels such as Mytilus edulis are able to produce a durable solid adhesive hold-fast from a mixture of proteins, rapidly (1-2 min), in an aqueous marine environment. A family of four of these proteins, known as M. edulis foot proteins (Mefp), each of which incorporates the unusual post-translationally modified amino acid L-3,4-dihydroxyphenylalanine (L-dopa), has been isolated from the phenol gland of M. edulis. Although it is known that these proteins self-assemble with other components to form the adhesive plaque, the (between-protein) interactions have not been characterized. The most intensely investigated protein in the Mefp family is Mefp-1. Attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR) is used to investigate the interaction of Mefp-1 and another well-characterized Mefp protein (Mefp-2) at a germanium (Ge) interface. The data show that Mefp-1 excludes Mefp-2 from the surface until the Mefp-1 adlayer is exposed to an oxidant. The data suggest that Mefp-2 adsorbs at least as strongly to Ge as Mefp-1.