Australian Biophysics Research presented at the Faraday Discussion Meeting on Peptide-Membrane Interactions

Australian Biophysics was well represented at the recent Faraday Discussion on Peptide-Membrane Interactions  with Prof Mibel Aguilar, A/Prof Ron Clarke and Dr Evelyne Deplazes presenting their work. 

The Faraday Discussions has been at the forefront of physical chemistry for well over 100 years. With its unique format of distributing papers in advance and its strong focus on discussion, Faraday Discussion meetings provide an excellent opportunity to engage with experts in the field. The meeting on Peptide-Membrane Interactions was held as a virtual meeting from September 8-10 and had over 150 participants.

Prof Mibel Aguilar presented her work on the impact of the antibacterial peptide maculatin 1.1 on E. coli membranes. Rather than using model membranes, the study used supported lipid membranes derived from exponential growth phase and stationary growth phase of the bacteria. Results from atomic force microscopy experiments revealed differences in lipid domain formation and membrane destruction during the two phases. This work is an ongoing collaboration with ASB members Prof Frances Separovi, Dr Marc Antoine Sani and Dr Gavin Reid from University of Melbourne.

A/Prof Ron Clarke talked about his work on the secondary structure of the N-termini in the Na+, K+ – and H+ , K+ -ATPase; a domain that has not been fully resolved in crystal structures of this important enzyme. Quartz crystal microbalance measurements of synthetic peptides that correspond to the N-termini of these proteins showed that these Lys-rich termini interact via an electrostatic interaction with PS-containing membranes. Circular dichroism experiments also revealed that membrane binding induces an increase in helical or other secondary structure content.

Dr Evelyne Deplazes from the University of Queensland presented a study combining MD simulations and electrical impedance spectroscopy to characterise the membrane pore formed by the pH-sensitive peptide GALA. The results from the combined in-silico and wet-lab experiments suggest that GALA pores likely consist of six peptide monomers rather than eight to twelve monomers, as previously reported. Analysis of the electrical impedance spectroscopy data indicates that GALA pores exhibit cation selectivity, which is based on ΔG_hydration of the ions. The work was a collaboration with ASB member Dr Charles Cranfield from University of Technology Sydney, and was recently published in the Journal of Physical Chemistry Letters.

Prof Mibel and A/Prof Ron Clarke are both past winners of the ASB McAuley Hope prize and Dr Evelyne Deplazes is a past ASB Young Biophysicist 

All oral papers presented at the meeting as well as transcripts of all discussion will be published in the Journal Faraday Discussions later this year.