Identification and Characterization of Adhesive Proteins in Freshwater Mussels for the Development of Novel Bioadhesives

Ng, Judith 1 ;  Rees, David 1 ;  Wojtas, Magdalena 1 ;  Sone, Eli 1, 2

1. Institute of Biomaterials and Biomedical Engineering, University of Toronto; 2. Faculty of Dentistry, University of Toronto

The European freshwater mollusks Dreissena bugensis (quagga mussel) and Dreissena polymorpha (zebra mussel) adhere to a variety of underwater surfaces via the byssus, a proteinaceous “anchor”, from which threads are secreted. The threads terminate in a small, disc-shaped adhesive plaque which have adapted to turbulent conditions with remarkable adhesive strength for their size. We propose to identify the proteins responsible for adhesion in both mussel species and to elucidate the molecular mechanisms by which they adhere. Top adhesive candidates that demonstrate evidence for an adhesive role in mussel plaque-substrate activity were determined via LC-MS/MS and relative quantification, and were subsequently purified, and characterized. Gel electrophoresis results indicated proteins in the zebra mussel bulk plaque and adhesive interface with expected sizes and banding patterns, with further proteomic analysis to come. A protocol was optimized to purify Dbfp7, a protein determined to be a top quagga mussel adhesive candidate from extensive proteomics analyses. Preliminary characterization of Dbfp7 was performed with surface-sensitive and optical analysis techniques. As a downstream goal, we aim to incorporate relevant protein motifs from these proteins into peptide mimics for the creation of novel bioadhesives for medical and dental applications. Understanding the molecular mechanisms and proteins responsible for adhesion in freshwater mussels will provide models for medical adhesives which function reliably on wet tissue surfaces with minimal inflammation.