α‐Latrotoxin‐stimulated GABA release can occur in Ca2+‐free, Na+‐free medium

FEBS Letters

Storchak, L.G.¹  Pozdnyakova, N.G.¹  Grishin, E.V.²  Pashkov, V.N.²  Himmelreich, N.H.¹ 

[1] Palladin Institute of Biochemistry, Ukrainian Academy of Sciences, ul. Leontovich 9, Kiev 252030, Ukraine;Shemyakin and Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, ul. Miklukho-Maklaya 16/10, 117871 GSP Moskow, V-437, Russian Federation

关键词: α-Latrotoxin;    Monoclonal antibody A4;    Rat brain synaptosome;    GABA release;    22Na infux;   

DOI  :  10.1016/0014-5793(94)00790-X

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

We have studied [¹⁴C]GABA release from synaptosomes induced by native and monoclonal antibodies-modified α-latrotoxin (LTX). Modification of LTX eliminates the toxin's ability to increase [Ca²⁺]_i influx into synaptosomes. It has been shown that native LTX does not change ²²Na influx into rat brain synaptosomes. Both toxin forms studied, native and modified by monoclonal antibodies, stimulate [¹⁴C]GABA release from synaptosomes in divalent-free medium where sodium was substituted by equimolar concentrations of choline chloride. Native toxin induces a more rapid stimulation of [¹⁴C]GABA release than the modified one. It was suggested that the difference in the mediator release rates is not accounted for by the inability of modified toxin to form active ion channels in synaptosomal plasmalemma, but most probably by the state of toxin-receptor complexes.

【 授权许可】

Unknown