Liszczyk, E. D. | bioRxiv Science

bioRxiv2026

A biofilm-derived peptide as an underwater adhesive

Wet adhesives that perform under water have broad applications in industrial and biomedical settings. To date, molecular designs for underwater adhesives have largely been inspired by marine animals including mussels and barnacles. Here, we propose bacterial biofilms as an alternative source of inspiration for underwater adhesives. Specifically, we demonstrate the application potential of a peptide derived from biofilms formed by the notorious pathogen Vibrio cholerae. We characterize the ability of this biofilm-derived peptide to adsorb onto various surfaces and to glue wet surfaces, by using a combination of confocal microscopy, molecular dynamics simulations, atomic force microscopy, lap shear tests, and spectroscopic tools. We further show that the peptide can co-aggregate with microspheres acting as an effective flocculant. Finally, we succeeded in purifying this peptide from E. coli in a functional form, setting the stage for large-scale production. Our results open new design possibilities for underwater adhesives inspired by natural biofilms. TeaserA peptide derived from biofilms adheres to diverse surfaces and shows promising potential as a wet adhesive and flocculant.

bioengineering↗

bioRxiv2026

Structure of a key adhesin-exopolysaccharide interaction provides insights into matrix assembly in Vibrio cholerae biofilms

Biofilms serve as a protective mechanism for bacteria, including many pathogens. To form such communities, bacteria secrete macromolecules that form an extracellular matrix serving as a barrier against environmental threats, such as predation, antibiotics, and the host immune system. To be effective, a biofilm must anchor to foreign surfaces and retain sufficient stiffness, in the environment or in a host. However, how this matrix self-organizes to support biofilm formation remains a mystery at the molecular level. The human pathogen Vibrio cholerae produces biofilms primarily composed of an exopolysaccharide called VPS (Vibrio polysaccharide), consisting of an unusually-modified repeating tetrasaccharide core unit. VPS engages with two secreted adhesion proteins, Bap1 and RbmC, which adhere the biofilm to abiotic and biotic surfaces, and serve to strengthen the biofilm by interacting with VPS using a conserved {beta}-propeller. To pinpoint the interaction between the adhesins and purified segments of VPS, we determined the [~]1.6 [A] X-ray crystal structure of Bap1 bound to fragmented VPS and used the structure to carry out molecular dynamics simulations. The structure revealed a single binding site consisting of one tetrasaccharide unit involving an induced magnesium binding site. Unexpectedly, the tetrasaccharide adopted a bent state caused by a rotation of the glycosidic bond between the central two monosaccharide units. Using a combination of mutagenesis, light scattering, and in situ fluorescent microscopy, we demonstrate that Bap1 not only facilitates biofilm adhesion, but is also required for proper VPS organization, through the identified binding pocket. Our structure reveals for the first time the interaction between a biofilm exopolysaccharide and matrix protein, as well as insights into conformational changes of exopolysaccharide induced by this binding. Our findings provide a generalizable approach for studying the biophysical and biochemical properties of carbohydrate-dependent biofilm assembly, which may lead to new ways to treat disease caused by biofilm-forming bacterial pathogens by disrupting the exopolysaccharide-protein interactions.

microbiology↗