Chemistry Seminar - The biological function of copper(II)-binding cyclic peptides from the Great Barrier Reef

Title:  The biological function of copper(II)-binding cyclic peptides from the Great Barrier Reef

Speaker:  Dr Phillip Baur, IMB

Abstract: Lissoclinum patella is found in the reefs around Heron Island and contains the symbiotic prokaryotic cyanobacteria Prochloron didemni, which produces patellamides, with a previously unknown biological function. In vitro studies have shown them to have an interesting and versatile copper(II) coordination chemistry, resulting in complexes with the ability to catalyze a range of chemical reactions. We uncovered a possible biological role for patellamides in metal ion coordination and carbonate transport. Patellamides and their complexes further demonstrated very high membrane permeability in PAMPA and CACO-2 assays. Combined with findings on intracellular pH in Prochloron didemni and the bioactivity of patellamide-copper solutions in algae, alongside the absence of typical CO₂-uptake mechanisms in P. didemni, we conclude that patellamides likely facilitate carbonate transport. This study provides unprecedented evidence linking cyanobactin production and function to metal-binding properties, suggesting that metal-related roles may be a widespread yet overlooked feature of this peptide family.

Bio: Philipp Baur completed his doctorate through the Max Planck School Matter to Life at University of Heidelberg in 2023 under the supervision of Prof. Peter Comba. His PhD research focused on the biological function of patellamides, a family of copper(II)-binding cyclic peptides produced by cyanobacteria associated with ascidians. He worked with both synthetic peptides and natural samples collected during field trips the UQ research station on Heron Island in the Great Barrier Reef. In 2024, he joined the Fairlie Group at the Institute for Molecular Bioscience (IMB), as a postdoctoral researcher. His current work focuses on developing membrane-permeable peptides and PROTAC-based drugs. Philipp’s research interests lie at the intersection of inorganic chemistry and peptide chemistry.