Ultrafast Protein Folding in Membrane-Mimetic Environments.
J Mol Biol
; 430(4): 554-564, 2018 02 16.
Article
em En
| MEDLINE
| ID: mdl-29128595
ABSTRACT
Proteins fold on timescales from hours to microseconds. In addition to protein size, sequence, and topology, the environment represents an equally important factor in determining folding speed. This is particularly relevant for proteins that require a lipid membrane or a membrane mimic to fold. However, only little is known about how properties of such a hydrophilic/hydrophobic interface modulate the folding landscape of membrane-interacting proteins. Here, we studied the influence of different membrane-mimetic micellar environments on the folding and unfolding kinetics of the helical-bundle protein Mistic. Devising a single-molecule fluorescence spectroscopy approach, we extracted folding and unfolding rates under equilibrium conditions and dissected the contributions from different detergent moieties to the free-energy landscape. While both polar and nonpolar moieties contribute to stability, they exert differential effects on the free-energy barrier Hydrophobic burial stabilizes the folded state but not the transition state in reference to a purely aqueous environment; by contrast, zwitterionic headgroup moieties stabilize the folded state and, additionally, lower the free-energy barrier to accelerate the folding of Mistic to achieve ultrafast folding times down to 35µs.
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Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Methanosarcina
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Dobramento de Proteína
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Proteínas Arqueais
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Proteínas de Membrana
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Membranas Artificiais
Idioma:
En
Ano de publicação:
2018
Tipo de documento:
Article