Noncompetitive inhibition of indolethylamine-N-methyltransferase by N,N-dimethyltryptamine and N,N-dimethylaminopropyltryptamine.
Noncompetitive inhibition of indolethylamine-N-methyltransferase by N,N-dimethyltryptamine and N,N-dimethylaminopropyltryptamine.
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DOI：
10.1021/bi500175p
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发表时间：
2014-05-13
期刊：
影响因子：
2.9
通讯作者：
Ruoho AE
中科院分区：
文献类型：
--
作者：
Chu UB;Vorperian SK;Satyshur K;Eickstaedt K;Cozzi NV;Mavlyutov T;Hajipour AR;Ruoho AE
吲哚乙胺-N-甲基转移酶（INMT）是一种1类甲基转移酶，已知其产生N，N-二甲基色胺（DMT），一种对各种肾上腺素能、肾上腺素能、组胺能、多巴胺能和σ-1受体具有亲和力的致幻剂。DMT通过INMT对内源性底物色胺和S-腺苷-L-甲硫氨酸（SAM）的作用产生。INMT酶活性的生物学、生物化学和选择性小分子调节在很大程度上仍然未知。动力学机制抑制兔肺INMT（rabINMT）的产品，DMT，并通过一种新的色胺衍生物进行了测定。在Michaelis-Menten和Lineweaver-Burk分析已被应用于研究抑制，DMT被发现是一个混合的竞争性和非竞争性抑制剂时，对色胺测量。新的色胺衍生物N-[2-（1H-吲哚-3-基）乙基]-N′，N′-二甲基丙烷-1，3-二胺（丙基二甲基氨基色胺或PDAT）对rabINMT的抑制作用为纯非竞争性机制，Ki值为84 μM。当针对结构相似的1类甲基转移酶（如人苯乙醇胺-N-甲基转移酶（hPNMT）和人烟酰胺-N-甲基转移酶（hNNMT））进行测试时，在2 mM时未观察到PDAT的抑制作用，表明对INMT具有选择性。INMT抑制的非竞争性机制的证明意味着存在抑制性变构位点。使用计算机建模软件Autodock和穿线到人INMT（hINMT）结构上的rabINMT序列（蛋白质数据库条目2A 14）的计算机模拟分析鉴定了酶的N-末端螺旋-环-螺旋非活性位点结合区。通过Autodock测定，DMT和PDAT与rabINMT的该区域结合的能量分别为-6.34和-7.58 kcal/mol。评估INMT的变构控制可能阐明INMT生物学基础的新生化途径。
Indolethylamine-N-methyltransferase (INMT) is a Class 1 transmethylation enzyme known for its production of N,N-dimethyltryptamine (DMT), a hallucinogen with affinity for various serotonergic, adrenergic, histaminergic, dopaminergic, and sigma-1 receptors. DMT is produced via the action of INMT on the endogenous substrates tryptamine and S-adenosyl-l-methionine (SAM). The biological, biochemical, and selective small molecule regulation of INMT enzyme activity remain largely unknown. Kinetic mechanisms for inhibition of rabbit lung INMT (rabINMT) by the product, DMT, and by a new novel tryptamine derivative were determined. After Michaelis–Menten and Lineweaver–Burk analyses had been applied to study inhibition, DMT was found to be a mixed competitive and noncompetitive inhibitor when measured against tryptamine. The novel tryptamine derivative, N-[2-(1H-indol-3-yl)ethyl]-N′,N′-dimethylpropane-1,3-diamine (propyl dimethyl amino tryptamine or PDAT), was shown to inhibit rabINMT by a pure noncompetitive mechanism when measured against tryptamine with a Ki of 84 μM. No inhibition by PDAT was observed at 2 mM when it was tested against structurally similar Class 1 methyltransferases, such as human phenylethanolamine-N-methyltransferase (hPNMT) and human nicotinamide-N-methyltransferase (hNNMT), indicating selectivity for INMT. The demonstration of noncompetitive mechanisms for INMT inhibition implies the presence of an inhibitory allosteric site. In silico analyses using the computer modeling software Autodock and the rabINMT sequence threaded onto the human INMT (hINMT) structure (Protein Data Bank entry 2A14) identified an N-terminal helix–loop–helix non-active site binding region of the enzyme. The energies for binding of DMT and PDAT to this region of rabINMT, as determined by Autodock, were −6.34 and −7.58 kcal/mol, respectively. Assessment of the allosteric control of INMT may illuminate new biochemical pathway(s) underlying the biology of INMT.
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DOI：
10.1126/science.1166127
发表时间：
2009-02-13
期刊：
Science (New York, N.Y.)
影响因子：
--
作者：
Fontanilla D;Johannessen M;Hajipour AR;Cozzi NV;Jackson MB;Ruoho AE
通讯作者：
Ruoho AE
影响因子：
--
作者：
Barker, S A;Monti, J A;Christian, S T
通讯作者：
Christian, S T
影响因子：
4.8
作者：
Bashtrykov, Pavel;Jankevicius, Gytis;Jeltsch, Albert
通讯作者：
Jeltsch, Albert
影响因子：
4.7
作者：
CALLAWAY, JC
通讯作者：
CALLAWAY, JC
影响因子：
2.9
作者：
Gee, CL;Tyndall, JDA;Martin, JL
通讯作者：
Martin, JL