A research team at POSTECH, led by Professor Dong Soo Hwang (Division of Environmental Science and Engineering, Division of Interdisciplinary Bioscience & Bioengineering, Graduate School of Convergence Science and Technology) and Research Professor Jimin Choi (POSTECH Institute of Environmental and Energy Technology), has uncovered the molecular mechanism behind the remarkable underwater adhesion of hairy mussels (Barbatia virescens). Their findings, published in Nature Communications, reveal an oxidation-independent adhesion process driven by interactions between EGF/EGF-like domains and GlcNAc-based biopolymers.
Marine organisms such as mussels and barnacles are renowned for their ability to adhere firmly to surfaces, even in wet environments. Nearly 40 years ago, researchers identified the epidermal growth factor (EGF) domain as a key component in mussel adhesive proteins. Since then, similar adhesive proteins have been discovered in a variety of organisms, including marine species, snails, and spiders. However, the precise mechanism behind EGF-based underwater adhesion remained elusive -- until now.
The POSTECH team uncovered this mechanism by investigating the byssusof hairy mussels, where proteins containing EGF/EGF-like domains bind strongly to N-acetylglucosamine (GlcNAc)-based biopolymers. Their experiments revealed that these proteins exhibit adhesion energy more than three times greater than widely recognized wet-adhesive proteins, such as mefp-5 (mussel foot protein) and suckerin (spider silk protein).
One of the study's most groundbreaking findings is that the EGF-GlcNAc adhesion mechanism does not rely on oxidation, a defining feature of traditional 3,4-dihydroxyphenylalanine (DOPA)-based adhesives. This oxidation-independent process results in reversible and durable adhesion, making it highly effective across a range of environments, whether wet or dry.
Research Professor Jimin Choi, the study's first author, explained, "GlcNAc is a component commonly found in biological tissues and biofilms, making it highly versatile for applications in bioelectronics, tissue engineering, antifouling coatings, and more." Professor Dong Soo Hwang emphasized the broader implications of their findings: "This research is a critical first step toward developing sustainable, high-performance underwater adhesives and medical-grade bioadhesives."
This work was supported by the National Research Foundation of Korea (NRF), with funding from the Ministry of Science and ICT and the Ministry of Education under the NRF's 2022 Basic Research Program.
