具有谷氨酸/N-甲基-D-天冬氨酸受体特征的蛋白质复合物的离子通道特性

Ion channel properties of a protein complex with characteristics of a glutamate/N-methyl-D-aspartate receptor.

作者信息

Aistrup G L, Szentirmay M, Kumar K N, Babcock K K, Schowen R L, Michaelis E K

机构信息

Department of Biochemistry, Center for Neurobiology and Immunology Research, University of Kansas, Lawrence 66045, USA.

出版信息

FEBS Lett. 1996 Sep 30;394(2):141-8. doi: 10.1016/0014-5793(96)00938-6.

DOI:10.1016/0014-5793(96)00938-6

PMID:8843152

Abstract

The functional reconstitution of glutamate receptor proteins purified from mammalian brain has been difficult to accomplish. However, channels activated by L-glutamate (L-Glu) and N-methyl-D-aspartate (NMDA) were detected in planar lipid bilayer membranes (PLMs) following the reconstitution of a complex of proteins with binding sites for NMDA receptor (NMDAR) ligands. The presence of glycine was necessary for optimal activation. A linear current-voltage relationship was observed with the reversal potential being zero. Channels activated by L-Glu had conductances of 23, 47 and 65 pS, and were suppressed partially by competitive and fully by noncompetitive inhibitors of NMDARs. Magnesium had little effect on the reconstituted channels.

摘要

从哺乳动物大脑中纯化的谷氨酸受体蛋白的功能重建一直难以实现。然而，在用具有N-甲基-D-天冬氨酸受体（NMDAR）配体结合位点的蛋白质复合物重建后，在平面脂质双分子层膜（PLM）中检测到了由L-谷氨酸（L-Glu）和N-甲基-D-天冬氨酸（NMDA）激活的通道。甘氨酸的存在对于最佳激活是必要的。观察到线性电流-电压关系，反转电位为零。由L-Glu激活的通道电导分别为23、47和65皮安，被NMDAR的竞争性抑制剂部分抑制，被非竞争性抑制剂完全抑制。镁对重建通道的影响很小。