Patel A
Neuroscience Branch, National Institute of Health, National Institute on Drug Abuse, Baltimore, MD 21224.
Neuroreport. 1993 Nov 18;5(2):157-60. doi: 10.1097/00001756-199311180-00016.
We have characterized binding of [125I]RTI-55 ((-)-2 beta-carbomethoxy-3 beta-(4-iodophenyl)tropane) to the dog caudate membrane and detergent solubilized dopamine transporter sites. The solubilized transporter was assayed by filtration over polyethylenimine treated Whatman GF/B filters. [125I]RTI-55 specifically binds to transporter sites in membranes and solubilized protein with Kd of 0.27 and 0.34 nM, respectively. The binding of [125I]RTI-55 to the membrane and solubilized transporter was inhibited by dopamine, norepinephrine and serotonin uptake inhibitors with rank order and potencies consistent with that of the dopamine transporter. Thus, similar pharmacological properties between membranes and solubilized dopamine transporters were retained upon solubilization. Rapid assay of solubilized protein will aid in monitoring transporter protein purification.
我们已对[125I]RTI-55（(-)-2β-甲氧羰基-3β-(4-碘苯基)托烷）与犬尾状核膜及经去污剂增溶的多巴胺转运体位点的结合进行了表征。通过在经聚乙烯亚胺处理的沃特曼GF/B滤膜上进行过滤来测定增溶的转运体。[125I]RTI-55分别以0.27和0.34 nM的解离常数特异性结合于膜及增溶蛋白中的转运体位点。多巴胺、去甲肾上腺素和5-羟色胺摄取抑制剂可抑制[125I]RTI-55与膜及增溶转运体的结合，其排序和效力与多巴胺转运体一致。因此，增溶后膜与增溶多巴胺转运体之间保留了相似的药理学特性。对增溶蛋白的快速测定将有助于监测转运体蛋白的纯化。
