Zapraszamy do udziału w seminarium Wydziału Inżynierii Materiałowej i Fizyki Technicznej Politechniki Poznańskiej oraz Oddziału Poznańskiego Polskiego Towarzystwa Fizycznego, które odbędzie się 13 kwietnia 2023 r. o godz. 11:45. Pani mgr Madhurima Chattopadhyay wygłosi seminarium w formie zdalnej pt. „Understanding the nature of lipid diffusion at perturbed hydration conditions using fluorescence correlation spectroscopy”.
(link do pokoju Seminarium: https://emeeting.put.poznan.pl/eMeeting/rys-gup-9is).
Understanding the nature of lipid diffusion at perturbed hydration conditions using fluorescence correlation spectroscopy
Madhurima Chattopadhyay1, Taras Sych2, Erdinc Sezgin2 and Lukasz Piatkowski1
1Institute of Physics, Poznan University of Technology, Piotrowo 3, 60-965 Poznan, Poland
2Science for Life Laboratory, Department of Women’s and Children’s Health, Karolinska Institutet, 17165, Solna, Sweden
Abstract
Lipid diffusion plays a central role in shaping the structural reorganization of the cell membrane, maintaining lipid homeostasis, and helps in cellular transport and signaling. The lateral mobility of phospholipids in membranes was shown to be highly dependent on their local hydration level and the activation energy of diffusion increases at reduced hydration conditions1,2. Using two variants of fluorescence correlation spectroscopy (point FCS and scanning FCS) and two benchmark dyes, we show that after the removal of bulk water, the mechanism of the lipid diffusion in the phase-separated biomimetic cell membrane is altered and lipids undergo anomalous sub-diffusion replacing free Brownian motion. We propose that dehydration induces temporarily immobile lipid pockets in the membrane that arise the anomaly of lipid diffusion. Local transient dehydration being an important intermediate step of various biological processes, e.g. neurotransmission, fertilization, viral entry, our results provide important implications to the mechanism of lipid diffusion in such perturbed hydration conditions.
References:
(1) Chattopadhyay, M.; Krok, E.; Orlikowska, H.; Schwille, P.; Franquelim, H. G.; Piatkowski, L. Hydration Layer of Only a Few Molecules Controls Lipid Mobility in Biomimetic Membranes. J. Am. Chem. Soc. 2021, 143.
(2) Chattopadhyay, M.; Krok, E.; Orlikowska-Rzeznik, H.; Piatkowski, L. Cooperativity between Sodium Ions and Water Molecules Facilitates Lipid Mobility in Model Cell Membranes. Chem. Sci. 2023.
