Active site mutant acetylcholinesterase interactions with 2-PAM, HI-6, and DDVP
Active site mutant acetylcholinesterase interactions with 2-PAM, HI-6, and DDVP
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DOI：
10.1016/j.bbrc.2006.02.056
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发表时间：
2006-04-14
影响因子：
3.1
通讯作者：
Taylor, P
中科院分区：
文献类型：
--
作者：
Kovarik, Z;Ciban, N;Taylor, P
我们使用小鼠重组野生型乙酰胆碱酯酶（AChE；EC 3.1.1.7）、丁酰胆碱酯酶（BChE；EC 3.1.1.8）和具有与 BChE 中结构等效位置处发现的残基类似的突变（Y337A、F295L、F297I、Y72N、Y124Q 和 W286A）的 AChE 突变体来寻找基础AChE 和 BChE 在以下反应中的分歧：两种肟的可逆抑制，有机磷化合物 DDVP 的渐进抑制。和肟辅助磷酸化酶的再激活。 AChE w.t. 的抑制酶-肟解离常数2-PAM和H1-6的BChE分别为150和46μM，340和27μM。引入的突变降低了两种肟的肟结合亲和力。 DDVP 逐渐抑制胆碱酯酶，以 104 至 10(5)/min/M 的速率产生对称的二甲基磷酸化酶缀合物。所有缀合物均实现了高程度的肟辅助再激活，但两种肟的磷酸化突变体的速率比 AChE w.t. 慢 10 倍。 (c) 2006 Elsevier Inc. 保留所有权利。
We used mouse recombinant wild-type acetylcholinesterase (AChE; EC 3.1.1.7), butyrylcholinesterase (BChE; EC 3.1.1.8), and AChE Mutants with mutations (Y337A, F295L, F297I, Y72N, Y124Q, and W286A) that resemble residues found at structurally equivalent positions in BChE, to find the basis for divergence between AChE and BChE in following reactions: reversible inhibition by two oximes, progressive inhibition by the organophosphorus compound DDVP,. and oxime-assisted reactivation of the phosphorylated enzymes. The inhibition enzyme-oxime dissociation constants of AChE w.t. were 150 and 46 mu M, of BChE 340 and 27 mu M for 2-PAM and H1-6, respectively. Introduced mutations lowered oxime binding affinities for both oximes. DDVP progressively inhibited cholinesterases yielding symmetrical dimethylphosphorylated enzyme conjugates at rates between 104 and 10(5)/min/M. A high extent of oxime-assisted reactivation of all conjugates was achieved, but rates by both oximes were up to 10 times slower for phosphorylated mutants than for AChE w.t. (c) 2006 Elsevier Inc. All rights reserved.