六甲铵、吩噻嗪类、普萘洛尔和麻黄素对乙酰胆碱酯酶carbamylation毒扁豆碱,涕灭威和西维因:活性位点之间的交互和乙酰胆碱酯酶的功能不同的外围网站。
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辛格AK, Spassova D
六甲铵、吩噻嗪类、普萘洛尔和麻黄素对乙酰胆碱酯酶carbamylation毒扁豆碱,涕灭威和西维因:活性位点之间的交互和乙酰胆碱酯酶的功能不同的外围网站。
比较生物化学杂志C杂志Toxicol性。1998年1月;119 (1):97 - 105。
- PubMed ID
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9568379 (在PubMed]
- 文摘
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毒扁豆碱,涕灭威和西维因的乙酰胆碱酯酶抑制剂(疼痛)。physostigmine-inhibited疼痛会在300 nm励磁和500 nm发射波长,但涕灭威和西维因抑制酶没有。这表明carbamylated活性中心不是荧光在疼痛。physostigmine-inhibited疼痛的荧光强度随基质(acetylthiocholine)浓度增加而降低,从而表明毒扁豆碱结合活性部位对荧光的发展至关重要。因此,physostigmine-inhibited疼痛会发出荧光的绑定trimethylpyrrolo [2, 3 b]吲哚(TMPI)的一部分,由毒扁豆碱的水解,周边站点在疼痛。physostigmine-inhibited酶的荧光强度降低inhibited-enzyme透析时30分钟,不激活酶或180分钟,充分激活酶。这表明透析水解AChE-TMPI复杂速度远远超过它激活carbamylated的疼痛。麻黄素、心得安、吩噻嗪类包括trifluoparazine (TPZ)引起的非竞争性抑制,而六甲铵竞争力抑制疼痛活动引起的。TPZ,绑定与疼痛,形成荧光TPZ-enzyme复杂。TPZ-AChE复杂的荧光强度是有效地减少了麻黄素,但不是通过普萘洛尔或六甲铵。 This indicates that TPZ and ephedrine bind to the same site in AChE which is different from the site/or sites to which propranolol or hexamethonium bind. Hexamethonium protected AChE from inhibition by carbamates and decreased the fluorescence intensity of the physostigmine-inhibited AChE. Phenothiazines and ephedrine did not modulate the enzyme inhibition or the fluorescence intensity of the physostigmine-inhibited AChE. Propranolol and TPZ potentiated the enzyme inhibition and increased the fluorescence intensity in the presence of physostigmine. These compounds, however, did not affect the inhibition of AChE by carbaryl or aldicarb. Ephedrine blocked the effects of TPZ, but did not alter the effects of propranolol on physostigmine-inhibited AChE. AChE, therefore, contains multiple peripheral binding sites which, upon binding to specific ligands, transduce differential signals to the active center.