Dataset Information

Membrane Protein Activity Induces Specific Molecular Changes in Nanodiscs Monitored by FTIR Difference Spectroscopy.

ABSTRACT: It is well known that lipids neighboring integral membrane proteins directly influence their function. The opposite effect is true as well, as membrane proteins undergo structural changes after activation and thus perturb the lipidic environment. Here, we studied the interaction between these molecular machines and the lipid bilayer by observing changes in the lipid vibrational bands via FTIR spectroscopy. Membrane proteins with different functionalities have been reconstituted into lipid nanodiscs: Microbial rhodopsins that act as light-activated ion pumps (the proton pumps NsXeR and UmRh1, and the chloride pump NmHR) or as sensors (NpSRII), as well as the electron-driven cytochrome c oxidase RsCcO. The effects of the structural changes on the surrounding lipid phase are compared to mechanically induced lateral tension exerted by the light-activatable lipid analogue AzoPC. With the help of isotopologues, we show that the ν(C = O) ester band of the glycerol backbone reports on changes in the lipids' collective state induced by mechanical changes in the transmembrane proteins. The perturbation of the nanodisc lipids seems to involve their phase and/or packing state. ¹³C-labeling of the scaffold protein shows that its structure also responds to the mechanical expansion of the lipid bilayer.

SUBMITTER: Baserga F

PROVIDER: S-EPMC9234331 | biostudies-literature | 2022

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Membrane Protein Activity Induces Specific Molecular Changes in Nanodiscs Monitored by FTIR Difference Spectroscopy.

Baserga Federico F Vorkas Antreas A Crea Fucsia F Schubert Luiz L Chen Jheng-Liang JL Redlich Aoife A La Greca Mariafrancesca M Storm Julian J Oldemeyer Sabine S Hoffmann Kirsten K Schlesinger Ramona R Heberle Joachim J

Frontiers in molecular biosciences 20220613

It is well known that lipids neighboring integral membrane proteins directly influence their function. The opposite effect is true as well, as membrane proteins undergo structural changes after activation and thus perturb the lipidic environment. Here, we studied the interaction between these molecular machines and the lipid bilayer by observing changes in the lipid vibrational bands <i>via</i> FTIR spectroscopy. Membrane proteins with different functionalities have been reconstituted into lipid ...[more]

PMID: 35769914

Similar Datasets

Project description:A phylloquinone molecule (2-methyl, 3-phytyl, 1, 4-naphthoquinone) occupies the A(1) binding site in photosystem 1 particles from Synechocystis sp. 6803. In menB mutant photosystem 1 particles from the same species, plastoquinone-9 occupies the A(1) binding site. By incubation of menB mutant photosystem 1 particles in the presence of phylloquinone, it was shown in another study that phylloquinone will displace plastoquinone-9 in the A(1) binding site. We describe the reconstitution of unlabeled ((16)O) and (18)O-labeled phylloquinone back into the A(1) binding site in menB photosystem 1 particles. We then produce time-resolved A(1)(-)/A(1) Fourier transform infrared (FTIR) difference spectra for these menB photosystem 1 particles that contain unlabeled and (18)O-labeled phylloquinone. By specifically labeling only the phylloquinone oxygen atoms we are able to identify bands in A(1)(-)/A(1) FTIR difference spectra that are due to the carbonyl (C=O) modes of neutral and reduced phylloquinone. A positive band at 1494 cm(-1) in the A(1)(-)/A(1) FTIR difference spectrum is found to downshift 14 cm(-1) and decreases in intensity on (18)O labeling. Vibrational mode frequency calculations predict that an antisymmetric vibration of both C=O groups of the phylloquinone anion should display exactly this behavior. In addition, phylloquinone that has asymmetrically hydrogen bonded carbonyl groups is also predicted to display this behavior. The positive band at 1494 cm(-1) in the A(1)(-)/A(1) FTIR difference spectrum is therefore due to the antisymmetric vibration of both C=O groups of one electron reduced phylloquinone. Part of a negative band at 1654 cm(-1) in the A(1)(-)/A(1) FTIR difference spectrum downshifts 28 cm(-1) on (18)O labeling. Again, vibrational mode frequency calculations predict this behavior for a C=O mode of neutral phylloquinone. The negative band at 1654 cm(-1) in the A(1)(-)/A(1) FTIR difference spectrum is therefore due to a C=O mode of neutral phylloquinone. More specifically, calculations on a phylloquinone model molecule with the C(4)=O group hydrogen bonded predict that the 1654 cm(-1) band is due to the non hydrogen bonded C(1)=O mode of neutral phylloquinone.

Dataset Information

Membrane Protein Activity Induces Specific Molecular Changes in Nanodiscs Monitored by FTIR Difference Spectroscopy.

Publications

Membrane Protein Activity Induces Specific Molecular Changes in Nanodiscs Monitored by FTIR Difference Spectroscopy.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets