Localization of the bioadhesive precursors of the sandcastle worm, Phragmatopoma californica (Fewkes)

Abstract

SUMMARYThe marine sandcastle worm bonds mineral particles together into underwater composite dwellings with a proteinaceous glue. The products of at least four distinct secretory cell types are co-secreted from the building organ to form the glue. Prominent hetereogeneous granules contain dense sub-granules of Mg and the (polyphospho)proteins Pc3A and B, as well as at least two polybasic proteins, Pc1 and Pc4, as revealed by immunolabeling with specific antibodies against synthetic peptides. Equally prominent homogeneous granules comprise at least two polybasic proteins, Pc2 and Pc5, localized by immunolabeling with antisynthetic peptide antibodies. The components of the sub-micrometer granule types are unknown, though positive staining with a redox-sensitive dye suggests the contents include o-dihydroxy-phenylalanine (dopa). Quantitative PCR and in situ hybridization demonstrated that a tyrosinase-like enzyme with a signal peptide was highly expressed in both the heterogeneous and homogeneous granules. The contents of the granules are poorly mixed in the secreted mixture that forms the glue. Subsequent covalent cross-linking of the glue may be catalyzed by the co-secreted tyrosinase. The first three parapodia of the sandcastle worm also contain at least two distinct secretory tissues. The Pc4 protein was immunolocalized to the anterior secretory cells and the tryosinase-like gene was expressed in the posterior secretory cells, which suggests these proteins may have multiple roles. Supplementary material available online at

Byssal proteins of the freshwater zebra mussel,Dreissena polymorpha

“…In Dpfp5, the Nterminus (residues 1-68) is also basic (pI 9.6) and completely lacks negative residues, whereas the rest of the protein has an acidic pI of 4.5. Charge separation has also been observed in an adhesive protein of the sandcastle worm (Phragmatopoma californica), pc-3A, which has an acidic N-terminus and basic C-terminus (Wang & Stewart 2012). Like zebra mussels, sandcastle worms also contain both acidic and basic proteins (Endrizzi & Stewart 2009;Stewart et al 2011).…”

Sea star tenacity mediated by a protein that fragments, then aggregates

“…Temporary adhesion, on the contrary, allows simultaneous adhesion and locomotion, thus enabling adult organisms to graze, hunt, or locate a mate, and larval forms to explore immersed surfaces before they metamorphose (e.g., the foot secretions of gastropod molluscs) (8)(9)(10). From a molecular point of view, most studies have focused on the permanent adhesives from mussels, tubeworms, and barnacles (7,11,12) because these organisms are important macrofoulers of marine structures and the characterization of their adhesives stoked, at least originally, by the need for improved antifouling strategies. Several unique adhesive proteins have been characterized and assigned specific bulk or surface functions.…”

Biotecnología marina y acuicultura

“…El pegamento está hecho de una mezcla de proteínas que pueden purificarse e incluso sintetizarse pero mucha de su fuerza adhesiva proviene de su estructura que se pierde en la purificación y de momento no se puede imitar artificialmente (Lee, Scherer y Messersmith, 2006). Mientras no se descubre cómo replicar la estructura del pegamento del mejillón los investigadores dirigen su atención a un gusano que mediante su pegamento une partículas de arena para organizar un tubo que le sirve como casa (Wang y Stewart, 2012). En este caso, se unen dos materiales similares (arena-arena), mientras que el mejillón une su biso a una roca húme-da.…”