TY - JOUR
T1 - Improvement of reconstitution of the Cl--translocating ATPase isolated from Acetabularia acetabulum into liposomes and several anion pump characteristics
AU - Ohhashi, Toshitaka
AU - Katsu, Takashi
AU - Ikeda, Mikiko
N1 - Funding Information:
This work was partly supported hy a Grant-in-Aid for Scientific Research (No. 63~,'""i i~nd No. 02044101) from the Ministry of Edueatio~i, Science and Cultme el Japan an,a by a grant from me .~apanese Science Promoting Society.
PY - 1992/4/29
Y1 - 1992/4/29
N2 - The improved reconstitution of the Mono Q-III fraction, a Cl--translocating ATPase, isolated from Acetabularia acetabulum (Ikeda et al. (1990) Biochemistry 29, 2057-2065) into liposomes rendered transport properties of this enzyme clear. The liposomes were prepared by the reversed-phase method using egg lecithin and cholesterol in a molar ration of 2:1 and the purified ATPase was incorporated into the liposomes by a dialysis for 3 h. About 80% of the ATPase was incorporated into the liposomes. The weight ratio of the enzyme to lipid was 1:400-600. A sigmoid curve was obtained when the Cl--transport activity of the enzyme was plotted against Cl- concentration. Hill's plot afforded a half-subsrate concentration [S]0.5 of 45 mM and a Hill's coefficient n of 2.33. Effects of Br- and F- on the Cl--transport were also examined in the reconstituted system, both halide ions decrease the 36Cl- efflux significantly. These kinetic data are in good agreement with the electrophysiological data presented by Tittor et al. (1983) J. Membr. Biol. 75, 129-139).
AB - The improved reconstitution of the Mono Q-III fraction, a Cl--translocating ATPase, isolated from Acetabularia acetabulum (Ikeda et al. (1990) Biochemistry 29, 2057-2065) into liposomes rendered transport properties of this enzyme clear. The liposomes were prepared by the reversed-phase method using egg lecithin and cholesterol in a molar ration of 2:1 and the purified ATPase was incorporated into the liposomes by a dialysis for 3 h. About 80% of the ATPase was incorporated into the liposomes. The weight ratio of the enzyme to lipid was 1:400-600. A sigmoid curve was obtained when the Cl--transport activity of the enzyme was plotted against Cl- concentration. Hill's plot afforded a half-subsrate concentration [S]0.5 of 45 mM and a Hill's coefficient n of 2.33. Effects of Br- and F- on the Cl--transport were also examined in the reconstituted system, both halide ions decrease the 36Cl- efflux significantly. These kinetic data are in good agreement with the electrophysiological data presented by Tittor et al. (1983) J. Membr. Biol. 75, 129-139).
KW - ATPase, Cl-
KW - Characterization
KW - Chloride translocation
KW - Reconstitution
KW - anion pump
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U2 - 10.1016/0005-2736(92)90235-E
DO - 10.1016/0005-2736(92)90235-E
M3 - Article
C2 - 1533790
AN - SCOPUS:0026504410
VL - 1106
SP - 165
EP - 170
JO - Biochimica et Biophysica Acta - Biomembranes
JF - Biochimica et Biophysica Acta - Biomembranes
SN - 0005-2736
IS - 1
ER -