Structure and Function of Barnacle Cement Proteins

Abstract

We can find various sessile organisms in the marine environment. The barnacle is typical of sessile animals which firmly attach to various substrata in water. The barnacle secretes proteinaceous cement from a cement gland to the space between the calcareous barnacle base and substratum for the adhesion (Saroyan et al., 1970; Dougherty, 1990). While amino acid compositions of cements in some species have been reported (Walker, 1972; Barnes & Blacktock, 1974), protein constituents have remained unstudied because of the cement insolubility. We faced at least two difficulties in our studies on underwater adhesive proteins. First problem was analysis of the insoluble protein, because the underwater adhesive is generally insolubilized after secretion from the animal (Waite, 1987). The second difficulty was measurement of specific adhesive activity.