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 inż. Hanna Orlikowska-Reźnik wygłosi seminarium w formie zdalnej pt. „A closer look at the biomimetic lipid membrane/water interface – the effect of cholesterol” (link do pokoju Seminarium: https://emeeting.put.poznan.pl/eMeeting/rys-gup-9is).
A closer look at the biomimetic lipid membrane/water interface– the effect of cholesterol
Hanna Orlikowska-Rzeznik1, Jan Versluis2, Huib J. Bakker2, and Lukasz Piatkowski1
1Faculty of Materials Engineering and Technical Physics, Poznan University of Technology, Poland
2AMOLF, Ultrafast Spectroscopy, The Netherlands
Abstract
Cholesterol is a key component of mammalian cell membranes and biomimetic drug-delivery vesicles. Itis well known for regulating the dynamics and structure of lipid bilayers as well as mediating membrane trafficking, signal transduction, and host-pathogen interactions. Yet, there is an ongoing debate regarding its effect on the hydration properties of membranes. The orientation of interfacial water molecules can affect theelectrical potential of the membranes as well as the strength and specificity of their interactions with peripheral proteins and other molecules,which in turn can affect their function. To address this, I employed surface-specific heterodyne-detected vibrational sum-frequency generation (HD-VSFG) spectroscopy to provide molecular-level insights into the effect of cholesterol on the hydration properties of zwitterionic lipid monolayers at the air/water interface. Results indicate that cholesterol reduces the anisotropic, non-uniform orientational distribution of interfacial water molecules but only when incorporated into the glycerophospholipid membrane. In the case of the sphingomyelin membrane (raft-like), it seems that it has no influence. This intriguing findingadds to the multiple actions of cholesterol toward lipid membranes and has important implications for our understanding ofcell membrane biophysics and designing biomimetic drug-deliverysystems.
Acknowledgments
This work has been supported by the Polish National Agency for Academic Exchange (NAWA) under the STER programme, Towards Internationalization of Poznan University of Technology Doctoral School (2022-2024). This work was co-financed from the budget funds allocated for science in the years 2019–2023 as a research project under the Diamond Grant program 0042/DIA/2019/48 and by National Science Centre, Poland 2020/37/B/ST4/01785.
