PhD project

Uperin (Antimicrobial peptides)

Uperin peptides (U3.x) are produced on the skin of Australian frogs. Uperins show unique features; they adapt various structures depending on circumstances. Uperin acquires a randomly coiled structure in pure water, a helical structure in the presence of bacteria to kill them and amyloid fibrils in the saline buffer for longer durability. This chameleon feature indicates the significance of amyloid in AMP, so peptides get stability and sustain for a longer time. My PhD focused on the pathway of structural transitions of Uperin AMPs, peptide-membrane interactions and their impact on amyloid formation.

• A key intermediate, called helical intermediate, has been found that plays a crucial roles in transitions from random coil to beta-sheet-rich aggregate and amyloid formations (shown in the above figure)

• The free energy landscape (shown below) revealed the aggregation pathway of Uperin peptides which undergo through helical intermediate

Bacterial membrane mimetics (TFE, liposome, micelle) modulate peptide's secondary structure and, thereby, level of amyloid formation (following results)