Abstract
Barnacle adhesion underwater is an important phenomenon to understand for the prevention of biofouling and potential biotechnological innovations, yet so far, identifying what makes barnacle glue proteins ‘sticky’ has proved elusive. Examination of a broad range of species within the barnacles may be instructive to identify conserved adhesive domains. We add to extensive information from the acorn barnacles (order Sessilia) by providing the first protein analysis of a stalked barnacle adhesive, Lepas anatifera (order Lepadiformes). It was possible to separate the L. anatifera adhesive into at least 10 protein bands using SDS-PAGE. Intense bands were present at approximately 30, 70, 90 and 110 kilodaltons (kDa). Mass spectrometry for protein identification was followed by de novo sequencing which detected 52 peptides of 7–16 amino acids in length. None of the peptides matched published or unpublished transcriptome sequences, but some amino acid sequence similarity was apparent between L. anatifera and closely-related Dosima fascicularis. Antibodies against two acorn barnacle proteins (ab-cp-52k and ab-cp-68k) showed cross-reactivity in the adhesive glands of L. anatifera. We also analysed the similarity of adhesive proteins across several barnacle taxa, including Pollicipes pollicipes (a stalked barnacle in the order Scalpelliformes). Sequence alignment of published expressed sequence tags clearly indicated that P. pollicipes possesses homologues for the 19 kDa and 100 kDa proteins in acorn barnacles. Homology aside, sequence similarity in amino acid and gene sequences tended to decline as taxonomic distance increased, with minimum similarities of 18–26%, depending on the gene. The results indicate that some adhesive proteins (e.g. 100 kDa) are more conserved within barnacles than others (20 kDa).
Highlights
Understanding the phenomenon of bioadhesion in wet or humid conditions may greatly aid biotechnological advances in the design of new surgical adhesives or biohybrid and biomimetic materials e.g., [1,2]
The protein separation results from the current study were compared to two investigations of the adhesive proteins of the stalked barnacle Dosima fascicularis, which is a close relative of L. anatifera [42,43] (Figure S1)
This study examines barnacle adhesive proteins across three taxonomic orders with the ultimate goal of identifying conserved adhesive domains in the entire group
Summary
Understanding the phenomenon of bioadhesion in wet or humid conditions may greatly aid biotechnological advances in the design of new surgical adhesives or biohybrid and biomimetic materials e.g., [1,2]. This knowledge will assist in the prevention of biofouling through design of smarter coatings and surfaces [3]. Posttranslational modifications of protein amino acids (AA) are utilised for adhesion and cohesion; L-3,4-dihydroxyphenylalanine (DOPA) is present in the adhesive proteins of marine and freshwater molluscs [9,10] and marine annelids [6]. Cross-bridges between phosphate groups may arise due to Ca2+, this has not been experimentally proven in the context of biological adhesives [12]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
