Acetylcholine receptor: Modification of synaptic gating mechanism after treatment with a disulfide bond reducing agent
Acetylcholine receptor: Modification of synaptic gating mechanism after treatment with a disulfide bond reducing agent
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乙酰胆碱受体：二硫键还原剂处理后突触门控机制的改变
DOI：
10.1007/bf00584796
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发表时间：
1975
期刊：
影响因子：
--
通讯作者：
K. Peper
中科院分区：
文献类型：
--
作者：
D. Ben;F. Dreyer;K. Peper
SummaryReduction of a ‘reactive’ disulfide bond in the postsynaptic membrane of the frog neuromuscular junction by dithiothreitol (DTT) decreases both the sensitivity of the membrane to applied acetylcholine (ACh) and the amplitude of the single ‘shot effect’. Analysis of ACh induced conductance fluctuations in voltage clamped frog endplates indicates that DTT reduces both the amplitude γ and duration τ of the elementary conductance events. The mean control value of γ was 18.5·10−12 Ω−1 with no significant dependence on temperature. The mean control values of τ were 2.3 msec at 7–9°C and 0.94 msec at 20–22°C. At 7–9°C 1 mM DTT (20–50 min after application) reduced γ to 61% of the control value and at 20–22°C to 39%, while τ was reduced to 70% at both temperature ranges. The dose-response curve for iontophoretically applied ACh indicates that neither the total number of ionic channels nor the cooperativity within the receptors are changed. However, the affinity of ACh for the receptor sites was reduced. All effects of DTT were fully reversed by the oxidizing agent 5,5′-dithio-bis-(2-nitrobenzoic acid) (DTNB).
