ATPase and proton-translocating activities in a plasma membrane-enriched fraction from cotyledons of Ricinus communis
ATPase and proton-translocating activities in a plasma membrane-enriched fraction from cotyledons of Ricinus communis
Sucrose gradient centrifugation was used to separate the microsomal membranes and purify the plasma membrane ATPase from Ricinus cotyledons. The pellet from a three-step (30, 34, 38%) sucrose gradient was enriched in plasma membrane as determined by a combination of marker assays.
The partially purified plasma membrane ATPase was magnesium-dependent and had a pH optimum of 6.5. It showed high sensitivity to vanadate, erythrosin B, SW 26, DCCD and PCMBS but low sensitivity to azide, nitrate and NEM. Substitution of calcium for magnesium resulted in low activity, and in the presence of magnesium, calcium was inhibitory. KCl stimulation was low (less than 50%) and of the potassium salts tested all were stimulatory except HCO−3
which was inhibitory. Specificity for nucleotide triphosphates was high, greatest activity occurring with ATP.
Proton-pumping activity measured using quinacrine fluorescence quenching was inhibited by vanadate and erythrosin B but not by nitrate and oligomycin indicating that activity was mainly due to the plasma membrane ATPase.
1205-1213
Williams, Lorraine E.
79ee1856-3732-492b-8ac5-239749c85d9e
Hall, J.L.
24cd62e9-4050-4514-9446-5a03949007f4
1 November 1989
Williams, Lorraine E.
79ee1856-3732-492b-8ac5-239749c85d9e
Hall, J.L.
24cd62e9-4050-4514-9446-5a03949007f4
Williams, Lorraine E. and Hall, J.L.
(1989)
ATPase and proton-translocating activities in a plasma membrane-enriched fraction from cotyledons of Ricinus communis.
Journal of Experimental Botany, 40 (11), .
(doi:10.1093/jxb/40.11.1205).
Abstract
Sucrose gradient centrifugation was used to separate the microsomal membranes and purify the plasma membrane ATPase from Ricinus cotyledons. The pellet from a three-step (30, 34, 38%) sucrose gradient was enriched in plasma membrane as determined by a combination of marker assays.
The partially purified plasma membrane ATPase was magnesium-dependent and had a pH optimum of 6.5. It showed high sensitivity to vanadate, erythrosin B, SW 26, DCCD and PCMBS but low sensitivity to azide, nitrate and NEM. Substitution of calcium for magnesium resulted in low activity, and in the presence of magnesium, calcium was inhibitory. KCl stimulation was low (less than 50%) and of the potassium salts tested all were stimulatory except HCO−3
which was inhibitory. Specificity for nucleotide triphosphates was high, greatest activity occurring with ATP.
Proton-pumping activity measured using quinacrine fluorescence quenching was inhibited by vanadate and erythrosin B but not by nitrate and oligomycin indicating that activity was mainly due to the plasma membrane ATPase.
This record has no associated files available for download.
More information
Published date: 1 November 1989
Identifiers
Local EPrints ID: 483952
URI: http://eprints.soton.ac.uk/id/eprint/483952
ISSN: 0022-0957
PURE UUID: d2ad6ed1-538d-4846-8fbb-8c84ad5a3dd7
Catalogue record
Date deposited: 07 Nov 2023 18:48
Last modified: 17 Mar 2024 05:17
Export record
Altmetrics
Contributors
Author:
J.L. Hall
Download statistics
Downloads from ePrints over the past year. Other digital versions may also be available to download e.g. from the publisher's website.
View more statistics