Peptide-membrane interactions

Biophysical characterization of the modes of peptide-membrane interactions is one of the major research focuses of the group. We, in the past, employed fluorescence correlation spectroscopy (FCS) to study different mechanisms through which model antimicrobial peptides (AMPs) interact with model membranes by monitoring the fraction of free peptide and membrane attached peptide. We have utilized Imaging FCS, recently developed by our group, to study peptide-membrane interactions in living systems.

Here we directly look at membrane dynamics which is used as a matric for the peptide induced membrane deformation. This approach helped us to decode a time and concentration dependent interaction of monomeric human islet amyloid polypeptide (hIAPP) with model and live cell membranes. In particular, we were able to show the temporal evolution of membrane dynamics after hIAPP addition as a time lapse ‘FCS movie’ which allows one to directly visualize concerted spatial change in membrane diffusion with pixel resolution. ‘FCS movies’, to the best of our knowledge, is the first demonstration of time lapse diffusion imaging. We are currently applying this method to assay the action of other peptides and other model AMPs.

hIAPP FCS movie

Reference:

Bag, N; Ali, A; Chauhan, VS; Wohland, T; Mishra, A. Membrane destabilization by monomeric hIAPP observed by imaging fluorescence correlation spectroscopy, Chem Commun (Camb). 49 (80) (2013) 9155-7.

  • NUS
  • Biophysical Fluorescence Laboratory