1: J Biochem (Tokyo)  1982 Dec;92(6):2043-6 

Nanosecond fluorometric investigation of hydrodynamic properties of adenosine
triphosphatase from thermophilic bacterium PS3.

Kinosita K Jr, Ikegami A, Yoshida M, Kagawa Y.

The soluble portion (TF1) of proton-translocating ATPase from thermophilic
bacterium PS3 was labeled with a fluorescent dye N-(1-pyrene)maleimide. The
decay of fluorescence anisotropy of the adduct showed that TF1 in aqueous
solution was characterized by a volume of equivalent sphere of 1,120 nm3. This
value is 2.4 times the volume calculated from the molecular weight and partial
specific volume, indicating a non-spherical shape and/or extensive hydration. A
prolate ellipsoid with an axial ratio of 2 to 3 is suggested as a first
approximation of the shape of hydrated TF1. The presence or absence of ATP, ADP,
or Mg2+ did not alter the volume of the equivalent sphere appreciably; the
probable conformational change of TF1 induced by these ligands does not lead to
a gross alteration of its hydrodynamic properties.

PMID: 6219102 [PubMed - indexed for MEDLINE]