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Proton‐motive‐force‐driven sucrose uptake in sugar beet plasma membrane vesicles
Author(s) -
Lemoine Rémi,
Delrot Serge
Publication year - 1989
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/0014-5793(89)80030-4
Subject(s) - vesicle , sucrose , chemistry , sugar beet , electrochemical gradient , membrane , chromatography , proton transport , biophysics , aqueous solution , biochemistry , biology , organic chemistry , horticulture
Highly purified plasma membranes were prepared by aqueous two‐phase partioning from sugar beet ( Beta vulgaris L.) leaf microsomes. Uptake of sucrose was studied with non‐energized vesicles and with vesicles artificially energized by a pH gradient (ΔpH) or a pH gradient plus an electrical gradient (ΔpH+Δψ). In non‐energized vesicles, sucrose was taken up via a diffusion‐like system until attainment of concentration equilibrium. Energized vesicles rapidly accumulated sucrose with accumulation ratios of 6 and 12 (vs the external concentration) for vesicles energized by ΔpH and ΔpH + Δψ, respectively. Energized uptake exhibited saturation kinetics, and was sensitive to carbonyl cyanide m ‐chlorophenylhydrazone and N ‐ethylmaleimide.