Cross-linking, DEER-spectroscopy and molecular dynamics confirm the inward facing state of P-glycoprotein in a lipid membrane.
J Struct Biol
; 211(1): 107513, 2020 07 01.
Article
em En
| MEDLINE
| ID: mdl-32339763
The drug efflux pump P-glycoprotein (P-gp) displays a complex transport mechanism involving multiple drug binding sites and two centres for nucleotide hydrolysis. Elucidating the molecular mechanism of transport remains elusive and the availability of P-gp structures in distinct natural and ligand trapped conformations will accelerate our understanding. The present investigation sought to provide biochemical data to validate specific features of these structures; with particular focus on the transmembrane domain that provides the transport conduit. Hence our focus was on transmembrane helices six and twelve (TM6/TM12), which are believed to participate in drug binding, as they line the central transport conduit and provide a direct link to the catalytic centres. A series of P-gp mutants were generated with a single cysteine in both TM6 and TM12 to facilitate measurement of inter-helical distances using cross-linking and DEER strategies. Experimental results were compared to published structures per se and those refined by MD simulations. This analysis revealed that the refined inward-facing murine structure (4M1M) of P-gp provides a good representation of the proximity, topography and relative motions of TM6 and TM12 in reconstituted human P-gp.
Palavras-chave
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Conformação Proteica
/
Membrana Celular
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Membro 1 da Subfamília B de Cassetes de Ligação de ATP
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Lipídeos de Membrana
Limite:
Animals
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Humans
Idioma:
En
Revista:
J Struct Biol
Assunto da revista:
BIOLOGIA MOLECULAR
Ano de publicação:
2020
Tipo de documento:
Article
País de afiliação:
Austrália