Marine Biotechnology Institute, Iwate, Japan.
FEBS J. 2012 May;279(10):1750-60. doi: 10.1111/j.1742-4658.2012.08552.x. Epub 2012 Mar 21.
Barnacles are a unique sessile crustacean that attach irreversibly and firmly to foreign underwater surfaces. Its biological underwater adhesive is a peculiar extracellular multi-protein complex. Here we characterize one of the two major proteins, a 52 kDa protein found in the barnacle cement complex. Cloning of the cDNA revealed that the protein has no homolog in the nonredundant database. The primary structure consists of four long sequence repeats. The process of dissolving the protein at the adhesive joint of the animal by various treatments was monitored in order to obtain insight into the molecular mechanism involved in curing of the adhesive bulk. Treatments with protein denaturant, reducing agents and/or chemical-specific proteolysis in combination with 2D diagonal PAGE indicated no involvement of the protein in intermolecular cross-linkage/polymerization, including formation of intermolecular disulfide bonds. As solubilization of the proteins required high concentrations of denaturing agents, it appears that both the conformation of the protein as building blocks and non-covalent molecular interactions between the building blocks, possibly hydrophobic interactions and hydrogen bonds, are crucial for curing of the cement. It was also suggested that the protein contributes to surface coupling by an anchoring effect to micro- to nanoscopic roughness of surfaces.
藤壶是一种独特的固着甲壳类动物，不可逆且牢固地附着在水下的异物表面上。其生物水下黏附剂是一种特殊的细胞外多蛋白复合物。在这里，我们对藤壶胶合物中的两种主要蛋白质之一进行了特征描述，这是一种 52kDa 的蛋白质。通过克隆 cDNA 发现，该蛋白质在非冗余数据库中没有同源物。其一级结构由四个长序列重复组成。通过对动物黏附处的蛋白质进行各种处理来溶解蛋白质的过程被监测，以便深入了解涉及黏附物固化的分子机制。用蛋白质变性剂、还原剂和/或化学特异性蛋白水解处理与二维对角线 PAGE 结合使用，表明该蛋白质不参与分子间交联/聚合，包括形成分子间二硫键。由于蛋白质的溶解需要高浓度的变性剂，因此似乎蛋白质作为构建块的构象以及构建块之间的非共价分子相互作用（可能是疏水相互作用和氢键）对于胶合物的固化至关重要。还提出了该蛋白质通过对微观到纳米级表面粗糙度的锚固作用有助于表面偶联。
