title: Stimulation of F(1)-ATPase activity by sodium dodecyl sulfate.
abstract: F(1)-ATPase is a rotary molecular motor in which the gamma subunit rotates inside the cylinder made of alpha(3)beta(3) subunits. We have studied the effects of sodium dodecyl sulfate (SDS) on the rotational and ATP hydrolysis activities of F(1)-ATPase. Bulk hydrolysis activity at various SDS concentrations was examined at 2mM ATP. Maximal stimulation was obtained at 0.003% (w/v) SDS, the initial (least inhibited) activity being about 1.4 times and the steady-state activity 3-4 times the values in the absence of SDS. Rotation rates observed with a 40-nm gold bead or a 0.29-mum bead duplex as well as the torque were unaffected by the presence of 0.003% SDS. The fraction of beads that rotated, in contrast, tended to increase in the presence of SDS. SDS seems to bring inactive F(1) molecules into an active form but it does not alter or enhance the function of already active F(1) molecules significantly.
authors.affiliation: Department of Physics, Faculty of Science and Engineering, Waseda University, Shinjuku-ku, Tokyo, Japan.
authors.forename: Mohammad Delawar
authors.initials: MD
authors.lastname: Hossain
authors.forename: Shou
authors.initials: S
authors.lastname: Furuike
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Onoue
authors.forename: Kengo
authors.initials: K
authors.lastname: Adachi
authors.forename: Masasuke
authors.initials: M
authors.lastname: Yoshida
authors.forename: Kazuhiko
authors.initials: K
authors.lastname: Kinosita
mesh_terms: D000255:Adenosine Triphosphate / Q000737:chemistry / Q000378:metabolism*; D001407:Bacillus / Q000201:enzymology; D001426:Bacterial Proteins / Q000737:chemistry / Q000378:metabolism*; D006868:Hydrolysis / Q000187:drug effects; D007700:Kinetics; D006180:Proton-Translocating ATPases / Q000737:chemistry / Q000378:metabolism*; D012967:Sodium Dodecyl Sulfate / Q000494:pharmacology*
chemical_list: D001426:Bacterial Proteins; D012967:Sodium Dodecyl Sulfate; D000255:Adenosine Triphosphate; D006180:Proton-Translocating ATPases