Dithiols and monothiols are linked with GABA transport in membrane vesicles of rat brain synaptosomes

FEBS Letters

Schaaf, J.M.¹  Teelken, A.W.¹  Robillard, G.T.² 

[1] Department of Neurology, University of Groningen, Oostersingel 59, Groningen, The Netherlands;Department of Physical Chemistry, University of Groningen, Nyenborgh 16, 9747 AG Groningen The Netherlands

关键词: Phenylarsine oxide;    N-Ethylmaleimide;    Sulfhydryl reagent;    Neurotransmitter;    γ-Aminobutyric acid;    GABA;    γ-aminobutyric acid;    NEM;    N-ethylmaleimide;    PCMBS;    p-chloromercuribenzenesulfonate;    Thorin;    4-(2-arsonophenyl)azo-3-hydroxy-2;    7-naphthalenedisulfonic acid;   

DOI  :  10.1016/0014-5793(87)80490-8

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

The properties of γ-aminobutyric acid (GABA) transport into membrane vesicles derived from synaptosomes of rat brain have been studied using membrane-permeable and -impermeable sulfhydryl reagents, dithiol-specific reagents and oxidizing reagents. GABA transport is inhibited, reversibly, by very low concentrations of the membrane-permeable trivalent arsenical, phenylarsine oxide. Preincubation with this reagent only partially protects GABA transport from inactivation by N-ethylmaleimide (NEM). Thorin, a negatively charged trivalent arsenical, has no influence on GABA transport at concentrations 100-fold higher than that of the inhibitory phenylarsine oxide. The impermeant oxidizing agent, potassium ferricyanide, did not inhibit transport whereas the permeant reagent, diamide, was inhibitory. These data indicate that the GABA transporter possesses an activity-linked dithiol in a hydrophobic region of the carrier not accessible to charged, polar reagents. p-Chloromercuribenzenesulfonate (PCMBS) also inhibits but does not protect against NEM inactivation, suggesting the occurrence of an activity-linked monothiol in a polar region of the carrier.

【 授权许可】

Unknown