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bioRxiv · 10.1101/2022.06.15.496244

The essential role of disulfide bonds for the hierarchical self-assembly and wet-adhesion of CP20-derived peptides

Baoshan Li, B. L.·Song, J.·Zeng, L.·Mao, T.·Ye, Z.·Hu, B.
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Abstract

Barnacles are typical fouling organisms which strongly adhere to immersed solid substrates by secreting proteinaceous adhesives called cement proteins (CPs). The self-assembly of the cement proteins forms a permanently bounded layer that binds barnacle to foreign surfaces. However, due to the abundance of cysteines in whole-length CP20, it is difficult to determine its natural structure and to properly describe its self-assembly properties. In this study, a putative functional motif of Balanus albicostatus CP20 (BalCP20) is identified and found to present distinctive self-assembly and wet-adhesion characteristics. The atomic force microscopy (AFM) and transmission electron microscope (TEM) investigations show that wildtype BalCP20-P3 forms grain-like spindles, which further assembly into fractal-like structures looks like ears of wheat. SDS-PAGE, AFM and LSCM show that DTT treatment opens up disulfide bonds between cysteines and disrupts the fractal-like structures (eras of wheat). Additionally, these morphologies are abolished when one of the BalCP20-P3 four cysteines is mutated by alanine. Circular dichroism (CD) results further suggest that the morphological diversity among BalCP20-P3 and its mutations lays on the proportion of -helix. The above results demonstrate that cysteines and disulfide bonds play a crucial role in the self-assembly of BalCP20-P3. This study provides new insights into BalCP20 underwater adhesion, and brings in new inspirations for the development of novel bionic underwater adhesive.

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Baoshan Li, B. L., Song, J., Zeng, L., Mao, T., Ye, Z., Hu, B.. 2022-06-15. The essential role of disulfide bonds for the hierarchical self-assembly and wet-adhesion of CP20-derived peptides. https://doi.org/10.1101/2022.06.15.496244

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