称谓
二甲基烯丙基二磷酸 二甲基烯丙基焦磷酸 Dimethylallyl pyrophosphate DMAPP
$结构式:$
-
\usepackage{chemfig}
\usetikzlibrary{decorations.pathmorphing}
\definecolor{cpk_P}{rgb}{1.00, 0.50, 0.00} % P
\definecolor{cpk_P6}{rgb}{0.50, 0.75, 0.50} % P6
\begin{document}
\chemfig[cram width=2pt]{
(-[2,]CH_3)(-[4.7]H_3C)=[7.3]-[0.7]-[7.3]O
-[0.7,1,,,,]{\chemmove{\draw[ultra thick,green,fill=cpk_P,line width=2pt] (0.1,0.12)circle(6pt);}P}
-[,1,,,decorate,decoration=snake]{\chemmove{\draw[ultra thick,green,fill=cpk_P,line width=2pt] (0.1,0.12)circle(6pt);}P}
}
\end{document}-
\usepackage{chemfig}
\definecolor{cpk_P}{rgb}{1.00, 0.50, 0.00} % P
\begin{document}
\chemfig{
-[6,0.5,,,,transparent] % 下边界支撑
-[0.7,1]
(-[2,1])
(=[7.3,1.2]
-[0.7,1]
(-[7.3,1]O
% P
(-[0,0.54,,,,transparent]{\chemmove{\draw[ultra thick,green,fill=cpk_P,line width=2pt] (0.1,0.12)circle(6pt);}P}
-[0,0.54,,,,transparent]{\chemmove{\draw[ultra thick,green,fill=cpk_P,line width=2pt] (0.1,0.12)circle(6pt);}P}
% 下边界支撑
-[6,0.5,,,,transparent])
% P
))
}
\end{document}^1
-
\usepackage{chemfig}
\usetikzlibrary{decorations.pathmorphing}
\definecolor{cpk_P}{rgb}{1.00, 0.50, 0.00} % P
\begin{document}
\chemfig[atom sep=2em,cram width=3pt]{
-[6,0.5,,,,transparent] % 下边界支撑
-[0.7,1]
(-[2,1])
(=[7.3,1.2]
-[0.7,1]
(-[7.3,1]O
% P
(
-[0.7,1,,,,]{\chemmove{\draw[ultra thick,green,fill=cpk_P,line width=2pt] (0.1,0.12)circle(6pt);}P}
-[,1,,,decorate,decoration=snake]{\chemmove{\draw[ultra thick,green,fill=cpk_P,line width=2pt] (0.1,0.12)circle(6pt);}P}
% 下边界支撑
-[6,0.5,,,,transparent])
% P
))
}
\end{document}^2
概述
二甲基烯丙基二磷酸(dimethylallyl diphosphate, DMAPP)是[[异戊二烯(isoprene)]]类化合物生物合成的两种基本前体之一,与[[异戊烯二磷酸(异戊烯基焦磷酸,IPP)]]互为异构体。其**结构**为含有一个双键的C5单元,通过焦磷酸基团活化,是萜类、[[0. 类胡萝卜素]]和[[胆固醇(cholesterol)]]等次生代谢产物合成的通用构建模块。
化学结构与性质
DMAPP的分子式为 {12}O_7P_2$,与IPP的区别在于双键位置:DMAPP的双键在C2-C3位(Δ²'³),而IPP的双键在C3-C4位(Δ³'⁴)。二者通过[[异戊二烯焦磷酸异构酶(IPI,IDI)]]相互转化。DMAPP中的烯丙基碳(C1)是亲电中心,使其能够发起"头对尾"缩合反应。
生物合成来源
DMAPP可经两条途径生成:
• **[[甲羟戊酸(甲瓦龙酸,MVA)]]途径(MVA途径)**:在动物、酵母和高等植物的细胞质中,由[[甲羟戊酸(甲瓦龙酸,MVA)]]经三步磷酸化和脱羧反应先生成IPP,再经IDI异构化为DMAPP
• **MEP途径**:在细菌和植物质体中,由甲基赤藓醇磷酸途径直接生成IPP和DMAPP
代谢调控与下游反应
DMAPP作为亲电引发剂,启动萜类链延伸反应:
1. DMAPP + IPP → GPP(牻牛儿基焦磷酸,C10,单萜前体) 2. GPP + IPP → FPP(法尼基焦磷酸,C15,倍半萜/[[胆固醇(cholesterol)]]前体) 3. FPP + IPP → GGPP(牻牛儿基牻牛儿基焦磷酸,C20,二萜/[[0. 类胡萝卜素]]前体)
IPP/DMAPP的比值受IDI活性调控,决定了萜类合成的代谢流量。
参考资料
• DMAPP也是tRNA异戊烯基化修饰的异戊烯基供体
• DMAPP/IPP比值的调控是[[异戊二烯(isoprene)]]代谢网络的核心调节点