Quantifying the Initial Unfolding of Bacteriorhodopsin Reveals Retinal Stabilization.
Angew Chem Int Ed Engl
; 58(6): 1710-1713, 2019 02 04.
Article
em En
| MEDLINE
| ID: mdl-30556941
ABSTRACT
The forces that stabilize membrane proteins remain elusive to precise quantification. Particularly important, but poorly resolved, are the forces present during the initial unfolding of a membrane protein, where the most native set of interactions is present. A high-precision, atomic force microscopy assay was developed to study the initial unfolding of bacteriorhodopsin. A rapid near-equilibrium folding between the first three unfolding states was discovered, the two transitions corresponded to the unfolding of five and three amino acids, respectively, when using a cantilever optimized for 2â
µs resolution. The third of these states was retinal-stabilized and previously undetected, despite being the most mechanically stable state in the whole unfolding pathway, supporting 150â
pN for more than 1â
min. This ability to measure the dynamics of the initial unfolding of bacteriorhodopsin provides a platform for quantifying the energetics of membrane proteins under native-like conditions.
Palavras-chave
Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Retina
/
Bacteriorodopsinas
Idioma:
En
Ano de publicação:
2019
Tipo de documento:
Article