ATP hydrolytic activity of an iron-stimulated P-type ATPase of mouse liver microsomes.
Mouse liver microsomes treated with octylthioglucoside were examined for iron-stimulated ATPase activity. The activity was about 6 mumol Pi/mg protein/hr under optimal conditions [300 mM KC1, 3 mM MgSO4, 10 mM glutathione(GSH), 100 microM FeCl3, 3 mM ATP and 50 mM acetate buffer at pH 5.0]. The Km for iron was 20 microM. A reducing agent, such as GSH or dithiothreitol, was required for the activity, and removal of Fe2+ from the reaction mixture by bathophenan-throlinedisulfonate resulted in a complete loss of the iron-stimulated ATPase activity. Vanadate inhibited the iron-stimulated ATPase activity. These results suggest that microsomes from mouse liver contain the Fe(2+)-stimulated P-type ATPase.
Takeda
K
K
Division of Molecular Cell Biology, School of Medicine, University of Occupational and Environmental Health, Japan, Yahatanishi-ku, Kitakyushu 807-8555, Japan.
Soeda
S
S
Arai
M
M
Kawamura
M
M
D000251:Adenosine Triphosphatases / Q000378:metabolism*; D000255:Adenosine Triphosphate / Q000378:metabolism*; D000818:Animals; D005978:Glutathione; D006868:Hydrolysis; D007501:Iron / Q000378:metabolism*; D051379:Mice; D008862:Microsomes, Liver / Q000201:enzymology*; D013863:Thioglucosides
D013863:Thioglucosides; C042989:n-octyl-beta-D-thioglucopyranoside; D000255:Adenosine Triphosphate; D007501:Iron; D000251:Adenosine Triphosphatases; D005978:Glutathione