Calcium ions induce glutamate transport into rat brain membrane vesicles in the absence of sodium and chloride evidence for a novel uptake site?

FEBS Letters

Harnecker, J.¹  Hollmann, M.¹  Seifert, W.¹ 

[1] Department of Neurobiology, Max-Planck-Institut für Biophysikalische Chemie Am Faßberg, D-3400 Göttingen, FRG

关键词: Ca2+;    Glutamate uptake;    Glutamate receptor binding;    Cl−-independent transport;   

DOI  :  10.1016/0014-5793(88)80588-X

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Evidence is presented that glutamate binding to rat brain synaptic plasma membranes measured in Cl⁻- and Na⁺-free but Ca²⁺-supplemented buffers is partly due to uptake of glutamate into resealed membrane vesicles. An intravesicular volume of 7.9 μl/mg protein was measured. Ca²⁺-induced glutamate binding to synaptic plasma membranes was found to be sensitive to low temperatures as well as to an increase in osmolarity and was abolished by short pulses of ultrasonication. None of several glutamate receptor agonists tested discriminated between basal and Ca²⁺-induced binding but 4 out of 5 glutamate uptake inhibitors did. The Ca²⁺-induced increase in glutamate binding was the same irrespective of whether calcium acetate, calcium sulfate or calcium gluconate in either Tris-acetate of Tris-citrate buffer was used.

【 授权许可】

Unknown