1. Adhesive Properties of Adsorbed Layers of Two Recombinant Mussel Foot Proteins with Different Levels of DOPA and Tyrosine
- Author
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Ali Miserez, Maria Penelope De Santo, Bruno Zappone, Pierluigi Bilotto, Kanagavel Deepankumar, Cristina Labate, School of Materials Science and Engineering, School of Biological Sciences, Biological & Biomimetic Material Laboratory @ NTU, and Center for Biomimetic Sensor Science
- Subjects
Surface Properties ,02 engineering and technology ,010402 general chemistry ,Microscopy, Atomic Force ,01 natural sciences ,Adsorption ,Adhesives ,Microscopy ,Electrochemistry ,Animals ,General Materials Science ,Amino Acid Sequence ,Tyrosine ,Spectroscopy ,Materials [Engineering] ,Chemistry ,Monomers ,Surface forces apparatus ,Surfaces and Interfaces ,Adhesion ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,Recombinant Proteins ,0104 chemical sciences ,Bivalvia ,Dihydroxyphenylalanine ,Peptides and Proteins ,Biophysics ,Mica ,Adhesive ,0210 nano-technology ,Layer (electronics) - Abstract
Using a surface forces apparatus and an atomic force microscope, we characterized the adhesive properties of adsorbed layers of two recombinant variants of Perna viridis foot protein 5 (PVFP-5), the main surface-binding protein in the adhesive plaque of the Asian green mussel. In one variant, all tyrosine residues were modified into 3,4-dihydroxy-l-phenylalanine (DOPA) during expression using a residue-specific incorporation strategy. DOPA is a key molecular moiety underlying underwater mussel adhesion. In the other variant, all tyrosine residues were preserved. The layer was adsorbed on a mica substrate and pressed against an uncoated surface. While DOPA produced a stronger adhesion than tyrosine in contact with the nanoscopic Si3N4 probe of the atomic force microscope, the two variants produced comparable adhesion on the curved macroscopic mica surfaces of the surface forces apparatus. These findings show that the presence of DOPA is not a sufficient condition to generate strong underwater adhesion. Surface chemistry and contact geometry affect the strength and abundance of protein-surface bonds created during adsorption and surface contact. Importantly, the adsorbed protein layer has a random and dynamic polymer-network structure that should be optimized to transmit the tensile stress generated during surface separation to DOPA surface bonds rather than other weaker bonds. National Research Foundation (NRF) We acknowledge financial support from the Marine Science Research and Development Program (MSRDP) of the Singapore National Research Foundation (NRF), Grant No. MSRDP-P29.
- Published
- 2019