Improvement of reconstitution of the Cl--translocating ATPase isolated from Acetabularia acetabulum into liposomes and several anion pump characteristics

Toshitaka Ohhashi, Takashi Katsu, Mikiko Ikeda

Research output: Contribution to journalArticle

9 Citations (Scopus)

Abstract

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).

Original languageEnglish
Pages (from-to)165-170
Number of pages6
JournalBBA - Biomembranes
Volume1106
Issue number1
DOIs
Publication statusPublished - Apr 29 1992

Keywords

  • ATPase, Cl-
  • Characterization
  • Chloride translocation
  • Reconstitution
  • anion pump

ASJC Scopus subject areas

  • Biophysics
  • Biochemistry
  • Cell Biology

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