A giant liposome for single-molecule observation of conformational changes in membrane proteins
Artikel i vetenskaplig tidskrift, 2009

We present an experimental system that allows visualization of conformational changes in membrane proteins at the single-molecule level. The target membrane protein is reconstituted in a giant liposome for independent control of the aqueous environments on the two sides of the membrane. For direct observation of conformational changes, an extra-liposomal site(s) of the target protein is bound to a glass surface, and a probe that is easily visible under a microscope, such as a micron-sized plastic bead, is attached to another site on the intra-liposomal side. A conformational change, or an angular motion in the tiny protein molecule, would manifest as a visible motion of the probe. The attachment of the protein on the glass surface also immobilizes the liposome, greatly facilitating its manipulation such as the probe injection. As a model system, we reconstituted ATP synthase (FOF1) in liposomes tens of mu m in size, attached the protein specifically to a glass surface, and demonstrated its ATP-driven rotation in the membrane through the motion of a submicron bead. (c) 2009 Elsevier B.V. All rights reserved.

kinetic mechanism

mitochondrial adenosine-triphosphatase

Single-molecule

resonance energy-transfer

stepwise rotation

flagellar motor

change

Giant liposome

escherichia-coli

ATP synthase

Conformational

channel

unilamellar vesicles

c-subunit ring

atp synthase

Membrane protein

Författare

Y. Onoue

The Graduate University for Advanced Studies (SOKENDAI)

Waseda University

T. Suzuki

Tokyo Institute of Technology

Japan Science and Technology Agency

M. Davidson

Chalmers University of Technology

Mattias Karlsson

Chalmers University of Technology

Owe Orwar

Chalmers, Kemi- och bioteknik, Fysikalisk kemi

M. Yoshida

Japan Science and Technology Agency

Tokyo Institute of Technology

K. Kinosita

Waseda University

Biochimica et Biophysica Acta - Biomembranes

0005-2736 (ISSN)

Vol. 1788 1332-1340

Ämneskategorier

Fysikalisk kemi

Kemi

DOI

10.1016/j.bbamem.2009.01.015