The kinetics of the active and de-energized transport of O-methyl glucose in Ustilago maydis

The kinetics of the uptake and efflux of 3-0-methyl-glucose in sporidia of Ustilago maydis were measured, both in active cells and in cells whose metabolic activity had been inhibited by azide and iodoacetate. The de-energized transport system proved to be carrier mediated with apparent affinity c...

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Main Authors: Miller, D. M., Harun, Salleh
Format: Article
Language:English
Published: Elsevier 1978
Online Access:http://psasir.upm.edu.my/id/eprint/33841/
http://psasir.upm.edu.my/id/eprint/33841/1/33841%20the%20kinetics.pdf
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author Miller, D. M.
Harun, Salleh
author_facet Miller, D. M.
Harun, Salleh
author_sort Miller, D. M.
building UPM Institutional Repository
collection Online Access
description The kinetics of the uptake and efflux of 3-0-methyl-glucose in sporidia of Ustilago maydis were measured, both in active cells and in cells whose metabolic activity had been inhibited by azide and iodoacetate. The de-energized transport system proved to be carrier mediated with apparent affinity constants 13 ± 2 mM outside (Ko) and 18 ± 2 mM inside (1\)). The apparent maximum rate constants for the same system were 0.66 ± 0,05 mmo l/l cell water per min for uptake (11+) and 0.53 ± 0.04 mmo l/l cell water' per mill for efflux (11_), For the active system Ko = 0,08 ± 0,01, K) > 40, \I, = 9.7 :':0,5 and V_ = l.lt 0.9 (in equivalent units). These results are discussed in the context of the carrier mechanism as proposed by Regen and Morgan (Regen, D.M. and Morgan, H, E, (1964) Biochim. Biophys. Acta 79, 151-166). The antifungal compound carboxin had no effect on de-energized transport hut was shown to decrease both Ko and 11+in the active system. Phloretin and phlorizin were also found to be without effect on de-energized cells but the former enhanced while the latter inhibited active uptake.
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spelling upm-338412019-10-21T02:33:46Z http://psasir.upm.edu.my/id/eprint/33841/ The kinetics of the active and de-energized transport of O-methyl glucose in Ustilago maydis Miller, D. M. Harun, Salleh The kinetics of the uptake and efflux of 3-0-methyl-glucose in sporidia of Ustilago maydis were measured, both in active cells and in cells whose metabolic activity had been inhibited by azide and iodoacetate. The de-energized transport system proved to be carrier mediated with apparent affinity constants 13 ± 2 mM outside (Ko) and 18 ± 2 mM inside (1\)). The apparent maximum rate constants for the same system were 0.66 ± 0,05 mmo l/l cell water per min for uptake (11+) and 0.53 ± 0.04 mmo l/l cell water' per mill for efflux (11_), For the active system Ko = 0,08 ± 0,01, K) > 40, \I, = 9.7 :':0,5 and V_ = l.lt 0.9 (in equivalent units). These results are discussed in the context of the carrier mechanism as proposed by Regen and Morgan (Regen, D.M. and Morgan, H, E, (1964) Biochim. Biophys. Acta 79, 151-166). The antifungal compound carboxin had no effect on de-energized transport hut was shown to decrease both Ko and 11+in the active system. Phloretin and phlorizin were also found to be without effect on de-energized cells but the former enhanced while the latter inhibited active uptake. Elsevier 1978 Article PeerReviewed application/pdf en http://psasir.upm.edu.my/id/eprint/33841/1/33841%20the%20kinetics.pdf Miller, D. M. and Harun, Salleh (1978) The kinetics of the active and de-energized transport of O-methyl glucose in Ustilago maydis. Biochimica et Biophysica Acta, 514 (2). pp. 320-331. ISSN 0006-3002 10.1016/0005-2736(78)90302-4
spellingShingle Miller, D. M.
Harun, Salleh
The kinetics of the active and de-energized transport of O-methyl glucose in Ustilago maydis
title The kinetics of the active and de-energized transport of O-methyl glucose in Ustilago maydis
title_full The kinetics of the active and de-energized transport of O-methyl glucose in Ustilago maydis
title_fullStr The kinetics of the active and de-energized transport of O-methyl glucose in Ustilago maydis
title_full_unstemmed The kinetics of the active and de-energized transport of O-methyl glucose in Ustilago maydis
title_short The kinetics of the active and de-energized transport of O-methyl glucose in Ustilago maydis
title_sort kinetics of the active and de-energized transport of o-methyl glucose in ustilago maydis
url http://psasir.upm.edu.my/id/eprint/33841/
http://psasir.upm.edu.my/id/eprint/33841/
http://psasir.upm.edu.my/id/eprint/33841/1/33841%20the%20kinetics.pdf