Radioiodinated azide and isothiocyanate derivatives of cocaine for irreversible labeling of dopamine transporters: synthesis and covalent binding studies.
Radioiodinated azide and isothiocyanate derivatives of cocaine for irreversible labeling of dopamine transporters: synthesis and covalent binding studies.
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DOI：
10.1021/bc0497214
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发表时间：
2005-04
影响因子：
4.7
通讯作者：
J. Lever;M. Zou;M. L. Parnas;R. Duval;S. Wirtz;J. B. Justice;R. Vaughan;A. Newman
中科院分区：
文献类型：
--
作者：
J. Lever;M. Zou;M. L. Parnas;R. Duval;S. Wirtz;J. B. Justice;R. Vaughan;A. Newman
用~(125)I标记了两种新的N-取代-3-苯基托烷生物碱，作为多巴胺转运体(DAT)结合部位的不可逆探针。一个含有用于光标记的碘芳基叠氮部分，而另一个含有用于直接结合的碘芳基异硫氰酸酯。这两种放射性配体都是在无载体的条件下，通过相应的苯胺的亲电放射性碘化，然后重氮化和叠氮化钠处理，或者在碱性条件下添加硫光气，在一瓶中制备的。具体合成了(-)-N-[4-(3-[(125)I]iodo-4-azidophenyl)butyl]-2beta-carbomethoxy-3beta-(4-chlorophenyl)tropane([~(125)I]MFZ-2-24)和(-)-N-[4-(3-[(125)I]iodo-4-isothiocyanophenyl)butyl]-2beta-carbomethoxy-3beta-(4-chlorophenyl)tropane([~(125)I]MFZ 3-37)。经反相高效液相色谱和固相萃取分离，平均产率分别为[(125)I]MFZ-2-24(67%，n=5)和[(125)I]MFZ-3-37(45%，n=3)，放化纯度高(96-99%)，放射性比活度高(>；2000 mci/微摩尔)。通过它们与大鼠纹状体膜的共价连接以及在80 kDa处与全长DAT相对应的单条放射性标记条带的免疫沉淀，证明了放射性配体的用途。
Two novel N-substituted-3beta-phenyltropane alkaloids have been labeled with iodine-125 for use as irreversible probes of dopamine transporter (DAT) binding sites. One contains an iodoaryl azide moiety for photolabeling, while the other bears an iodoaryl isothiocyanate for direct conjugation. Both radioligands were prepared in a one-flask procedure by electrophilic radioiodination of the corresponding aniline under no-carrier-added conditions, followed either by diazotization and treatment with sodium azide, or by addition of thiophosgene under basic conditions. Specifically, (-)-N-[4-(3-[(125)I]iodo-4-azidophenyl)butyl]-2beta-carbomethoxy-3beta-(4-chlorophenyl)tropane ([(125)I]MFZ-2-24) and (-)-N-[4-(3-[(125)I]iodo-4-isothiocyanophenyl)butyl]-2beta-carbomethoxy-3beta-(4-chlorophenyl)tropane ([(125)I]MFZ 3-37) were synthesized. Isolation by reversed-phase HPLC and solid-phase extraction gave good average yields of [(125)I]MFZ-2-24 (67%, n = 5) and [(125)I]MFZ-3-37 (45%, n = 3) with high radiochemical purities (96-99%) and specific radioactivities (>2000 mCi/micromol). The utility of the radioligands was demonstrated by their covalent linkage to rat striatal membranes, and immunoprecipitation of a single radiolabeled band at 80 kDa corresponding to the full-length DAT.