Strictosidine synthase (STR) is a key enzyme involved in the biosynthesis of terpenoid indole alkaloids (TIA) by condensing tryptamine and secologanin into strictosidine. The transgenic tobacco plants targeting STR to...Strictosidine synthase (STR) is a key enzyme involved in the biosynthesis of terpenoid indole alkaloids (TIA) by condensing tryptamine and secologanin into strictosidine. The transgenic tobacco plants targeting STR to subcellular compartments were established to express STR in chloroplast, vacuole and endoplasmic reticulum (ER) by the tobacco stable transformation. It was shown that STR was effectively expressed in the above subcellular compartments by Western blot analysis and STR enzymatic assay. In vitro , STR enzymatic assay was measured indirectly by fluorimetrically detecting depletion of tryptamine feeding on secologanin in the reaction mixture. The tryptamine were completely depleted by STR in the crude extract of leaves of transgenic tobacco plants targeting and expressing STR in the chloroplast, vacuole and ER, which ascertained the STR functionally targeted to the three subcellular compartments. To confirm STR correct targeting and expressing in chloroplast, the chloroplasts were isolated and the fractions of purified chloroplasts were analyzed by Western blot. The hypothesis of STR correct targeting to the chloroplast was tested. The results have implications on our understanding of the complex intracellular trafficking in metabolic intermediates of TIA biosynthesis.展开更多
Terpenoid indole(TIAs)andβ-carboline alkaloids(BCAs),such as suppressant reserpine,vasodilatory yohimbine,and antimalarial quinine,are natural compounds derived from strictosidine.These compounds can exert powerful p...Terpenoid indole(TIAs)andβ-carboline alkaloids(BCAs),such as suppressant reserpine,vasodilatory yohimbine,and antimalarial quinine,are natural compounds derived from strictosidine.These compounds can exert powerful pharmacological effects but be obtained from limited source in nature.the whole biosynthetic pathway of TIAs and BCAs,The Pictet–Spengler reaction catalyzed by strictosidine synthase(STR;EC:4.3.3.2)is the rate-limiting step.Therefore,it is necessary to investigate their biosynthesis pathways,especially the role of STR,and related findings will support the biosynthetic generation of natural and unnatural compounds.This review summarizes the latest studies concerning the function of STR in TIA and BCA biosynthesis,and illustrates the compounds derived from strictosidine.The substrate specificity of STR based on its structure is also summarized.Proteins that contain sixbladed four-strandedβ-propeller folds in many organisms,other than plants,are listed.The presence of these folds may lead to similar functions among organisms.The expression of STR gene can greatly influence the production of many compounds.STR is mainly applied to product various valuable drugs in plant cell suspension culture and biosynthesis in other carriers.展开更多
文摘Strictosidine synthase (STR) is a key enzyme involved in the biosynthesis of terpenoid indole alkaloids (TIA) by condensing tryptamine and secologanin into strictosidine. The transgenic tobacco plants targeting STR to subcellular compartments were established to express STR in chloroplast, vacuole and endoplasmic reticulum (ER) by the tobacco stable transformation. It was shown that STR was effectively expressed in the above subcellular compartments by Western blot analysis and STR enzymatic assay. In vitro , STR enzymatic assay was measured indirectly by fluorimetrically detecting depletion of tryptamine feeding on secologanin in the reaction mixture. The tryptamine were completely depleted by STR in the crude extract of leaves of transgenic tobacco plants targeting and expressing STR in the chloroplast, vacuole and ER, which ascertained the STR functionally targeted to the three subcellular compartments. To confirm STR correct targeting and expressing in chloroplast, the chloroplasts were isolated and the fractions of purified chloroplasts were analyzed by Western blot. The hypothesis of STR correct targeting to the chloroplast was tested. The results have implications on our understanding of the complex intracellular trafficking in metabolic intermediates of TIA biosynthesis.
基金supported by the National Natural Science Foundation of China(Nos.81872933 and 81173119)the National Natural Science Foundation of China and Xinjiang Uygur Autonomous Region of China(No.U1130303)+1 种基金the Technology Cooperation Projects of Science in Shanghai,China(No.20015800100)the Key Project of Ministry of Science and Technology of China(No.2018ZX09731016-004)。
文摘Terpenoid indole(TIAs)andβ-carboline alkaloids(BCAs),such as suppressant reserpine,vasodilatory yohimbine,and antimalarial quinine,are natural compounds derived from strictosidine.These compounds can exert powerful pharmacological effects but be obtained from limited source in nature.the whole biosynthetic pathway of TIAs and BCAs,The Pictet–Spengler reaction catalyzed by strictosidine synthase(STR;EC:4.3.3.2)is the rate-limiting step.Therefore,it is necessary to investigate their biosynthesis pathways,especially the role of STR,and related findings will support the biosynthetic generation of natural and unnatural compounds.This review summarizes the latest studies concerning the function of STR in TIA and BCA biosynthesis,and illustrates the compounds derived from strictosidine.The substrate specificity of STR based on its structure is also summarized.Proteins that contain sixbladed four-strandedβ-propeller folds in many organisms,other than plants,are listed.The presence of these folds may lead to similar functions among organisms.The expression of STR gene can greatly influence the production of many compounds.STR is mainly applied to product various valuable drugs in plant cell suspension culture and biosynthesis in other carriers.
