Dynamics of bacteriorhodopsin 2D crystal observed by high-speed atomic force microscopy.
We have used high-speed atomic force microscopy to study the dynamics of bacteriorhodopsin (bR) molecules at the free interface of the crystalline phase that occurs naturally in purple membrane. Our results reveal temporal fluctuations at the crystal edges arising from the association and dissociation of bR molecules, most predominantly pre-formed trimers. Analysis of the dissociation kinetics yields an estimate of the inter-trimer single-bond energy of -0.9kcal/mol. Rotational motion of individual bound trimers indicates that the inter-trimer bond involves W10-W12 tryptophan residues.
Yamashita
Hayato
H
Department of Physics, Kanazawa University, Kakuma-machi, Kanazawa, Japan. yhayato@stu.kanazawa-u.ac.jp
Voïtchovsky
Kislon
K
Uchihashi
Takayuki
T
Contera
Sonia Antoranz
SA
Ryan
John F
JF
Ando
Toshio
T
D001436:Bacteriorhodopsins / Q000737:chemistry*; D018360:Crystallography, X-Ray; D007700:Kinetics; D018625:Microscopy, Atomic Force / Q000379:methods*; D009038:Motion; D018717:Purple Membrane; D013816:Thermodynamics; D014364:Tryptophan
D001436:Bacteriorhodopsins; D014364:Tryptophan