Barrettides: A Peptide Family Specifically Produced by the Deep-Sea Sponge Geodia barretti

• Published in: Journal of Natural Products
• Main Authors: Steffen, Karin, Laborde, Quentin, Gunasekera, Sunithi, Payne, Colton D., Rosengren, K. Johan, Riesgo Gil, Ana, Göransson, Ulf, Cárdenas, Paco
• Other Authors: Swedish Pharmaceutical Society, European Commission
• Format: Article in Journal/Newspaper
• Language: English
• Published: ACS Publications 2021
• Subjects: North Atlantic
• Online Access: http://hdl.handle.net/10261/257781; https://doi.org/10.1021/acs.jnatprod.1c00938; https://doi.org/10.13039/501100000780

Natural product discovery by isolation and structure elucidation is a laborious task often requiring ample quantities of biological starting material and frequently resulting in the rediscovery of previously known compounds. However, peptides are a compound class amenable to an alternative genomic, transcriptomic, and in silico discovery route by similarity searches of known peptide sequences against sequencing data. Based on the sequences of barrettides A and B, we identified five new barrettide sequences (barrettides C−G) predicted from the North Atlantic deep-sea demosponge Geodia barretti (Geodiidae). We synthesized, folded, and investigated one of the newly described barrettides, barrettide (NVVPCFCVEDETSGAKTCIPDNCDASRGTNP, disulfide connectivity I−IV, II−III). Co-elution experiments of synthetic and sponge-derived barrettide C confirmed its native conformation. NMR spectroscopy and the anti-biofouling activity on larval settlement of the bay barnacle Amphibalanus improvisus (IC50 0.64 μM) show that barrettide C is highly similar to barrettides A and B in both structure and function. Several lines of evidence suggest that barrettides are produced by the sponge itself and not one of its microbial symbionts. K.S. thanks the Swedish pharmaceutical society (Apotekarsocieteten) for funds provided to purchase reagents for SPPS. K.S., A.R., and P.C. acknowledge SponGES; SponGES has received funding from the European Union’s Horizon 2020 research and innovation program under grant agreement no. 679849. Peer reviewed