Stoichiometries of acetylcholine uptake, release, and drug inhibition in Torpedo synaptic vesicles: heterogeneity in acetylcholine transport and storage.
Stoichiometries of acetylcholine uptake, release, and drug inhibition in Torpedo synaptic vesicles: heterogeneity in acetylcholine transport and storage.
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鱼雷突触小泡中乙酰胆碱摄取、释放和药物抑制的化学计量：乙酰胆碱运输和储存的异质性。
DOI：
10.1111/j.1471-4159.1986.tb00639.x
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发表时间：
1986
影响因子：
4.7
通讯作者：
Parsons,SM
中科院分区：
文献类型：
--
作者：
Anderson,DC;Bahr,BA;Parsons,SM
高度纯化的鱼雷电器官突触小泡形成 1 mg 蛋白质/ml 的 49 nM 悬浮液。在主动转运条件下，每个囊泡可以积累数百个 [3H] 乙酰胆碱 ([3H]ACh) 分子，这需要 ACh 转运蛋白经历多次周转。转运阻滞剂反式-2-(4-苯基哌啶基)环己醇 (AH5183) 对囊泡储存内源性乙酰胆碱没有影响。相比之下，AH5183、其他阻断药物和非放射性 ACh 导致每个囊泡快速释放至少 30-63 个新转运的 [3H]ACh 分子。因此，AH5183将最近转运的“新”囊泡ACh与“旧”内源ACh区分开来。l-AH5183以16±7nMat 12nM囊泡和115±34nMat 120nM囊泡的半抑制浓度抑制ACh的转运。假设 AH5183 以非放大方式作用于受体，每个囊泡需要占据约 2.7 个或更少的受体才能抑制 ACh 转运。 AH5183 释放的每个囊泡的 [3H]ACh 分子数量明显增加，表明 AH5183 通过区分新旧 ACh 的间接机制抑制 ACh 储存。
Highly purifiedTorpedoelectric organ synaptic vesicles form a 49 nMsuspension at 1 mg protein/ml. Under active transport conditions hundreds of molecules of [3H]acetylcholine ([3H]ACh) can be accumulated per vesicle, which requires the ACh transporter to undergo multiple turnovers. The transport blockertrans‐2‐(4‐phenylpiperidino)cyclohexanol (AH5183) has no effect on storage of endogenous ACh by vesicles. In contrast, AH5183, other blocking drugs, and nonradioactive ACh caused a rapid release of at least 30–63 molecules of newly transported [3H]ACh per vesicle. Thus AH5183 distinguishes recently transported “new” vesicular ACh from “old” endogenous ACh.l‐AH5183 inhibits transport of ACh with a half‐inhibitory concentration of 16 ± 7 nMat 12 nMvesicles and 115 ± 34 nMat 120 nMvesicles. With the assumption that AH5183 acts on a receptor in an unamplified manner about 2.7 or fewer receptors per vesicle need to be occupied to cause inhibition of ACh transport. The apparent amplification in the number of [3H]ACh molecules per vesicle that are released by AH5183 suggests that AH5183 inhibits ACh storage by an indirect mechanism that distinguishes new from old ACh.