TY  - JOUR
A1  - Schmitt, Clemens Nikolaus Zeno
A1  - Winter, Alette
A1  - Bertinetti, Luca
A1  - Masic, Admir
A1  - Strauch, Peter
A1  - Harrington, Matthew J.
T1  - Mechanical homeostasis of a DOPA-enriched biological coating from mussels in response to metal variation
JF  - Interface : journal of the Royal Society
N2  - Protein metal coordination interactions were recently found to function as crucial mechanical cross-links in certain biological materials. Mussels, for example, use Fe ions from the local environment coordinated to DOPA-rich proteins to stiffen the protective cuticle of their anchoring byssal attachment threads. Bioavailability of metal ions in ocean habitats varies significantly owing to natural and anthropogenic inputs on both short and geological spatio-temporal scales leading to large variations in byssal thread metal composition; however, it is not clear how or if this affects thread performance. Here, we demonstrate that in natural environments mussels can opportunistically replace Fe ions in the DOPA coordination complex with V and Al. In vitro removal of the native DOPA metal complexes with ethylenediaminetetraacetic acid and replacement with either Fe or V does not lead to statistically significant changes in cuticle performance, indicating that each metal ion is equally sufficient as a DOPA cross-linking agent, able to account for nearly 85% of the stiffness and hardness of the material. Notably, replacement with Al ions also leads to full recovery of stiffness, but only 82% recovery of hardness. These findings have important implications for the adaptability of this biological material in a dynamically changing and unpredictable habitat.
KW  - mussel byssus
KW  - DOPA
KW  - metal coordination
KW  - coating
Y1  - 2015
U6  - https://doi.org/10.1098/rsif.2015.0466
SN  - 1742-5689
SN  - 1742-5662
VL  - 12
IS  - 110
PB  - Royal Society
CY  - London
ER  - 
TY  - JOUR
A1  - Degtyar, Elena
A1  - Harrington, Matthew J.
A1  - Politi, Yael
A1  - Fratzl, Peter
T1  - The mechanical role of metal ions in biogenic protein-based materials
JF  - Angewandte Chemie : a journal of the Gesellschaft Deutscher Chemiker ; International edition
N2  - Protein-metal interactions-traditionally regarded for roles in metabolic processes-are now known to enhance the performance of certain biogenic materials, influencing properties such as hardness, toughness, adhesion, and self-healing. Design principles elucidated through thorough study of such materials are yielding vital insights for the design of biomimetic metallopolymers with industrial and biomedical applications. Recent advances in the understanding of the biological structure-function relationships are highlighted here with a specific focus on materials such as arthropod biting parts, mussel byssal threads, and sandcastle worm cement.
KW  - adhesives
KW  - biomaterials
KW  - metal coordination
KW  - sacrificial bonds
KW  - self-healing materials
Y1  - 2014
U6  - https://doi.org/10.1002/anie.201404272
SN  - 1433-7851
SN  - 1521-3773
VL  - 53
IS  - 45
SP  - 12026
EP  - 12044
PB  - Wiley-VCH
CY  - Weinheim
ER  -