MEMBRANE DESTABILIZATION BY MONOMERIC HIAPP OBSERVED AT THE SINGLE MOLECULE LEVEL BY IMAGING FLUORESCENCE CORRELATION SPECTROSCOPY

by Nirmalya Bag, Ashraf Ali, Virander Singh Chauhan, Thorsten Wohland and Aseem Mishra

Chem Commun 2013, 49, 9155–9157

Monomeric hIAPP significantly destabilizes both model and live cell membranes by increasing membrane fluidity. This interaction with membranes happens via carpet formation followed by lipid extraction in a concentration dependent manner and thus we propose that hIAPP aggregation prior to membrane interaction may not be necessary for its cytotoxicity.

‘FCS movie’ of live cell membranes upon exposure to the membrane-active peptide amylin

The lateral diffusion of the cell membrane is mapped by imaging fluorescence correlation spectroscopy (Imaging FCS) with 240 nm spatial resolution and 1 ms temporal resolution over a large membrane area (5´5 mm²). We created a 60-minute FCS time lapse movie to follow membrane dynamics upon interaction with amylin (hIAPP), a peptide involved in insulin secretion. The movie shows how the peptide interacts with the bilayer and changes diffusion patterns with time (blue areas forming with advancing time).

Read online: Royal Society Chemistry.

Learn more about Thorsten Wohland’s research.