The strategy of robust adhesion employed by barnacles renders them fascinating biomimetic candidates for developing novel wet adhesives. Particularly, barnacle cement protein 19k (cp19k) has been speculated to be the key adhesive protein establishing the priming layer in the initial barnacle cement construction. In this work, we systematically studied the sequence design rationale of cp19k by designing adhesive peptides inspired by the low-complexity STGA-rich and the charged segments of cp19k. Combining structure analysis and the adhesion performance test, we found that cp19k-inspired adhesive peptides possess excellent disparate adhesion strategies for both hydrophilic mica and hydrophobic self-assembled monolayer surfaces. Specifically, the low-complexity STGA-rich segment offers great structure flexibility for surface adhesion, while the hydrophobic and charged residues can contribute to the adhesion of the peptides on hydrophobic and charged surfaces. The adaptive adhesion strategy identified in this work broadens our understanding of barnacle adhesion mechanisms and offers valuable insights for designing advanced wet adhesives with exceptional performance on various types of surfaces.
Keywords: barnacle; hydrogen bonds; hydrophobic interactions; peptide; wet adhesion.