Na predavanju će biti riječi o melitinu, peptidnom toksinu koji ubija stanice uništavajući staničnu membranu. Razumijevanje mehanizma kojim melitin i drugi membrano-aktivni peptidi remete stanične membrane može dovesti do novih metoda liječenja i razvoja anitbiotika.

Prof. Separovic je biofizički kemičar, a specijalizirala se u području NMR spektroskopije. Razvila je NMR tehnike solidnog stanja za određivanje strukture i dinamike membranskih komponenata in situ i fokusirala se na istraživanja peptidnih antibiotika i toksina u fosolipidnim membranama.

Doktorirala je na Sveučilištu New South Wales paralelno radeći za australsku nacionalnu znanstvenu agenciju CSIRO. Nakon 23 godine rada u CSIRO-u i jedne godine provedene na National Institutes of Health (SAD) pridružila se Sveučilištu u Melbourneu (1996). Voditelj je School of Chemistry, a njen laboratorij smješten je u sklopu Instituta Bio21.

U razdoblju od 2001. do 2011. objavila je 173 znanstvena rada i organizirala 35 velikih znanstvenih skupova. Dobitnik je Robertson Medal koju dodjeljuje Australian Society for Biophysics (2009) i ANZMAG Medal koju dodjeljuje The Australian and New Zealand Society for Magnetic Resonance (2011). Izabrana je za Fellow of the Biophysical Society (USA) i Fellow of the Australian Academy of Science (2012).

Predsjednik je Australian New Zealand Society for Magnetic Resonance (ANZMAG), član uredništva časopisa Concepts in Magnetic Resonance and Accounts in Chemical Research i urednik u Biochimica Biophysica Acta – Biomembranes, and European Biophysics Journal.

Sažetak predavanja

Most of us have felt the effect of a bee sting - but how does it actually work? The sting contains a peptide toxin, melittin, which kills cells by destroying the cell membrane. Understanding the mechanism by which melittin and other membrane-active peptides disrupt cell membranes may lead to new disease treatments and antibiotics.

Modern nuclear magnetic resonance (NMR) techniques enable in situ study of the structure and dynamics of membrane molecules and the effects of toxins and antibiotics to be unravelled. Solid-state NMR studies of aligned phospholipid membranes have been used to determine the orientation and location of antimicrobial peptides obtained from Australian tree frogs and amyloid peptides from Alzheimer’s disease.

Although the detailed structure of these peptides in membranes is difficult to determine as they disrupt the membrane bilayer, their three dimensional structure and mechanism of action has been elucidated. A range of solid-state NMR techniques was used to determine the conformation and mobility of these membrane-active peptides in order to understand how they exert their biological effect that leads to the disruption of bacterial or neuronal membranes.

The effect of the antimicrobial peptides on a variety of model membranes is strongly dependent on the lipid composition of the bilayer and correlates with selectivity for bacterial membranes and antibiotic activity. Likewise, the membrane interactions and structural changes of amyloid peptides from Alzheimer’s disease depend on the presence of cholesterol and metal ions, which have been implicated in the disease.