Chlorophyll-free chromoplasts from daffodil contain most of the enzymes for chlorophyll synthesis in a highly active form.
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.
Lützow
M
M
Institut für Biologie II, Universität Freiburg, Federal Republic of Germany.
Kleinig
H
H
D000622:Aminolevulinic Acid / Q000378:metabolism; D002734:Chlorophyll / Q000096:biosynthesis*; D002736:Chloroplasts / Q000201:enzymology*; D002851:Chromatography, High Pressure Liquid; D002855:Chromatography, Thin Layer; D007700:Kinetics; D010944:Plants / Q000201:enzymology*; D000623:Porphobilinogen Synthase / Q000378:metabolism; D011166:Porphyrins / Q000302:isolation & purification
D011166:Porphyrins; D002734:Chlorophyll; D000622:Aminolevulinic Acid; D000623:Porphobilinogen Synthase