Biochemical Mechanisms in Barnacle Adhesion

Tufts University, Medford MA

Investigators

Abstract

Barnacles create major problems worldwide related to biofouling in marine environments due to their growth on ships, docks and related structures. This biofouling results in the loss and destruction of structures in marine environments as well as loss of ship efficiency during transit due to increased drag resistance. Current options to control this growth of barnacles are either unsatisfactory or environmentally unacceptable. The mechanisms by which barnacles respond in the environment to adhere to different substrates are unknown. The goal of this project is to identify the key components in the 'glue' secreted by the barnacle, Balanus crenatus, in order to develop an understanding of the mechanisms involved in their adhesion to environmental surfaces in marine environments. The rationale for this study is that once we understand the mechanisms of barnacle adhesion, we should be in a position to design better strategies to control or prevent this process. In the long run, this insight into mechanisms of barnacle glue curing should also serve as a basis for the design and development of adhesives that cure in water, such as for biomedical applications. Our preliminary data suggest that the mechanisms of adhesion by barnacles are distinct from the mechanisms reported for mussels such as Mytilus edulis, which has been well-studied. The approach planned for the program is centered on isolating and characterizing the components of the glue used by the barnacle to stick to surfaces. More specifically, we plan the following steps in the process: (1) isolation and characterization of the proteins present in the glue of the barnacle, B. crenatus, (2) cloning and expression of genes from the barnacle that encode the proteins found in the glue, and (3) characterization of the barnacle adhesion and cement curing process by studying the proteins that are produced and their interactions. These studies will provide the most comprehensive picture of the mechanisms of barnacle adhesion and cement curing available to date and also provide insight into how this marine animal responds to environmental substrate cues. Our preliminary data illustrate the feasibility of the proposed plans since we have gained important initial insight into: (a) some of the proteins present in the adhesive plaques, (b) some of the genes encoding the proteins present in the adhesive plaques, and (c) methods to assess changes in the proteins upon addition of chemicals that influence changes in the adhesion environment and the protein interactions involved (e.g., metals/chelation chemicals and changes in oxidation-reduction state). This type of information and insight into adhesion and curing mechanisms will be critical to identifying mechanisms used by the barnacle to adhere to surfaces. With the plans to elucidate the mechanisms of adhesion of barnacles to surfaces, control of these surface interactions will then be feasible. This insight will be critical in order to identify long-term solutions to barnacle substrate colonization which leads to excessive pier and ship repairs and repainting, and the avoidance of the use of toxic compounds such as copper-based chemicals in material coatings to prevent barnacle adhesion in marine waters.