Detection of bacteriorhodopsin trimeric rotation at thermal phase transitions of purple membrane in suspension.
Biophys Chem
; 300: 107074, 2023 09.
Article
de En
| MEDLINE
| ID: mdl-37421867
Bacteriorhodopsin (bR) of purple membrane (PM) is a retinal protein that forms aggregates in the form of trimers constituting, together with archaeal lipids, the crystalline structure of PM. The rotary motion of bR inside PM may be pertinent in understanding the essence of the crystalline lattice. An attempt has been made to determine the rotation of bR trimers which has been found to be detected solely at thermal phase transitions of PM, namely lipid, crystalline lattice and protein melting phase transitions. The temperature dependences of dielectric versus electronic absorption spectra of bR have been determined. The results suggest that the rotation of bR trimers, together with concomitant bending of PM, are most likely brought by structural changes in bR which might be driven by retinal isomerization and mediated by lipid. The rupturing of the lipid-protein contact might consequently lead to rotation of trimers associated with bending, curling or vesicle formation of PM. So the retinal reorientation may underlie the concomitant rotation of trimers. Most importantly, rotation of trimers might play a role, in terms of the essence of the crystalline lattice, in the functional activity of bR and may serve physiological relevance.
Mots clés
Texte intégral:
1
Collection:
01-internacional
Base de données:
MEDLINE
Sujet principal:
Bactériorhodopsines
/
Membrane pourpre
Type d'étude:
Diagnostic_studies
Langue:
En
Journal:
Biophys Chem
Année:
2023
Type de document:
Article
Pays de publication:
Pays-Bas