Lützow M, Kleinig H
Institut für Biologie II, Universität Freiburg, Federal Republic of Germany.
Arch Biochem Biophys. 1990 Feb 15;277(1):94-100. doi: 10.1016/0003-9861(90)90555-d.
Chromoplasts isolated from chlorophyll-free daffodil flowers utilize in vitro delta-aminolevulinic acid (ALA) as precursor for the synthesis of large amounts of at least nine different products. Their identification as intermediates of the chlorophyll biosynthetic pathway demonstrates the presence of the majority of the respective enzymes in this nongreen plastid preparation. Porphobilinogen synthase was investigated more closely and found to be similar in its properties to the corresponding enzyme from other plastid sources. Protoporphyrin IX was also accepted as a substrate by chromoplast homogenate; here, as in the case of ALA as a substrate, Mg-protoporphyrin IX monomethyl ester was the last product formed. Formation of the isocyclic chlorophyll ring was not observed.
从不含叶绿素的水仙花中分离出的有色体在体外利用δ-氨基乙酰丙酸(ALA)作为前体,合成至少九种不同的产物。将它们鉴定为叶绿素生物合成途径的中间体,表明在这种非绿色质体制剂中存在大多数相应的酶。对胆色素原合酶进行了更深入的研究,发现其性质与来自其他质体来源的相应酶相似。原卟啉IX也被有色体匀浆接受为底物;在这里,与以ALA为底物的情况一样,镁原卟啉IX单甲酯是最后形成的产物。未观察到异环叶绿素环的形成。