Ultrafast force-clamp spectroscopy of single molecules reveals load dependence of myosin working stroke.
Nat Methods
; 9(10): 1013-9, 2012 Oct.
Article
em En
| MEDLINE
| ID: mdl-22941363
We describe a dual-trap force-clamp configuration that applies constant loads between a binding protein and an intermittently interacting biological polymer. The method has a measurement delay of only â¼10 µs, allows detection of interactions as brief as â¼100 µs and probes sub-nanometer conformational changes with a time resolution of tens of microseconds. We tested our method on molecular motors and DNA-binding proteins. We could apply constant loads to a single motor domain of myosin before its working stroke was initiated (0.2-1 ms), thus directly measuring its load dependence. We found that, depending on the applied load, myosin weakly interacted (<1 ms) with actin without production of movement, fully developed its working stroke or prematurely detached (<5 ms), thus reducing the working stroke size with load. Our technique extends single-molecule force-clamp spectroscopy and opens new avenues for investigating the effects of forces on biological processes.
Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Análise Espectral
/
Miosinas
Limite:
Animals
Idioma:
En
Ano de publicação:
2012
Tipo de documento:
Article