Effect of encapsulated protein on the dynamics of lipid sponge phase: a neutron spin echo and molecular dynamics simulation study
Artikel i vetenskaplig tidskrift, 2022

Lipid membranes are highly mobile systems with hierarchical, time and length scale dependent, collective motions including thickness fluctuations, undulations, and topological membrane changes, which play an important role in membrane interactions. In this work we have characterised the effect of encapsulating two industrially important enzymes, β-galactosidase and aspartic protease, in lipid sponge phase nanoparticles on the dynamics of the lipid membrane using neutron spin echo (NSE) spectroscopy and molecular dynamics (MD) simulations. From NSE, reduced membrane dynamics were observed upon enzyme encapsulation, which were dependent on the enzyme concentration and type. By fitting the intermediate scattering functions (ISFs) with a modified Zilman and Granek model including nanoparticle diffusion, an increase in membrane bending rigidity was observed, with a larger effect for β-galactosidase than aspartic protease at the same concentration. MD simulations for the system with and without aspartic protease showed that the lipids relax more slowly in the system with protein due to the replacement of the lipid carbonyl-water hydrogen bonds with lipid-protein hydrogen bonds. This indicates that the most likely cause of the increase in membrane rigidity observed in the NSE measurements was dehydration of the lipid head groups. The dynamics of the protein itself were also studied, which showed a stable secondary structure of protein over the simulation, indicating no unfolding events occurred.

Författare

Jennifer Gilbert

Lunds universitet

Inna Ermilova

Chalmers, Fysik, Nano- och biofysik

Michihiro Nagao

University of Maryland

National Institute of Standards and Technology (NIST)

University of Delaware

Jan Swenson

Chalmers, Fysik, Nano- och biofysik

T. Nylander

Lunds universitet

Lund Institute of Advanced Neutron and X-ray Science (LINXS)

Nanoscale

2040-3364 (ISSN) 2040-3372 (eISSN)

Vol. In Press

Ämneskategorier

Fysikalisk kemi

Biofysik

Teoretisk kemi

DOI

10.1039/d2nr00882c

PubMed

35470842

Mer information

Senast uppdaterat

2022-06-08