Abundance of Escherichia coli F1-ATPase molecules observed to rotate via single-molecule microscopy with gold nanorod probes.
The abundance of E. coli F1-ATPase molecules observed to rotate using gold nanorods attached to the gamma-subunit was quantitated. Individual F1 molecules were determined to be rotating based upon time dependent fluctuations of red and green light scattered from the nanorods when viewed through a polarizing filter. The average number of F1 molecules observed to rotate in the presence of GTP, ATP, and without nucleotide was approximately 50, approximately 25, and approximately 4% respectively. In some experiments, the fraction of molecules observed to rotate in the presence of GTP was as high as 65%. These data indicate that rotational measurements made using gold nanorods provide information of the F1-ATPase mechanism that is representative of the characteristics of the enzyme population as a whole.
School of Life Sciences, Arizona State University, P.O. Box 874501, Tempe, AZ 85287-4501, USA.
Justin
J
York
David
D
Spetzler
Tassilo
T
Hornung
Robert
R
Ishmukhametov
James
J
Martin
Wayne D
WD
Frasch
D029968:Escherichia coli Proteins; D006046:Gold; D053768:Metal Nanoparticles; D008853:Microscopy; D020409:Molecular Motor Proteins; D015336:Molecular Probe Techniques; D015335:Molecular Probes; D036103:Nanotechnology / Q000379:methods; D043942:Nanotubes; D006180:Proton-Translocating ATPases / Q000032:analysis / Q000378:metabolism*; D012399:Rotation
D029968:Escherichia coli Proteins; D020409:Molecular Motor Proteins; D015335:Molecular Probes; D006046:Gold; D006180:Proton-Translocating ATPases