The Disputation will be live streamed for everyone else.
The livestream will be activated 15 minutes before the Defense starts.
Trial lecture
June 6th, 10:15 AM, Auditorium 3, Chemistry building
Trial lecture title: The function, form, and production mechanism of vesicles in gram-positive and gram-negative bacteria
Kreeringssammendrag/Conferral summary
Antimikrobielle peptider, også kjent som AMP-er, har stort potensiale som nye alternativer til konvensjonell antibiotika, men er begrenset av bivirkninger og en manglende forståelse av deres molekylære virkemåte. Denne avhandlingen tar for seg vekselvirkningene mellom flere naturlige antimikrobielle peptider og lipidmembraner. Sentrale funn er at AMP-er kan permeabilisere cellemembranen uten å danne tradisjonelle porer, og føre til restrukturering av heterogene membraner.
Main research findings
Antimicrobial peptides (AMPs) are promising alternatives to conventional antibiotics, which are becoming less effective due to the rapid increase in antibiotic resistance. AMPs are highly effective against a wide range of bacteria, and at the same time have a lower risk of causing resistance. However, these peptides can be degraded by enzymes in the body and can become toxic against human cells at higher concentrations. This, together with a limited understanding of how they function on a molecular level, makes it highly challenging to use them as antibiotic drugs.
This thesis investigates the interactions between several natural AMPs with carefully designed model membranes, using small angle neutron and X-ray scattering. Among the key findings is that AMPs can effectively permeabilize lipid membranes without forming structural pores. Rather, transient channels are formed because of AMP-induced lipid flip-flop. Additionally, AMPs are shown to increase the line-tension in phase-separated membranes, resulting in substantial lateral restructuring of the membrane. This is a previously unexplored effect of AMPs which can contribute towards explaining their activity and cytotoxicity.
Candidate contact information
LinkedIn: linkedin.com/in/vladimir-koynarev
E-post: vladi.koynarev@gmail.com
Adjudication committee
Professor Cecilia Leal
University of Illinois, United States of America
Professor Uri Raviv
Hebrew University, Israel
Professor Unni Olsbye
Department of Chemistry, University of Oslo, Norway
Supervisors
Professor Reidar Lund
Department of Chemistry, University of Oslo, Norway
Professor Michele Cascella
Department of Chemistry, University of Oslo, Norway
Chair of defence
Professor Harald Walderhaug
Department of Chemistry, University of Oslo, Norway