Separation of Mg-Protoporphyrin IX and Mg-Protoporphyrin IX Monomethyl Ester Synthesized de novo by Developing Cucumber Etioplasts.
High pressure liquid chromatography was used to demonstrate that chelation of Mg(2+) into protoporphyrin IX precedes methylation in isolated greening etioplasts from cucumber (Cucumis sativus L. var. Beit Alpha) cotyledons. Mg-protoporphyrin IX synthesized in vitro from protoporphyrin IX, Mg(2+), and ATP or exogenous Mg-protoporphyrin IX could serve as substrates for the methylation step. In either case, S-adenosylmethionine was the methyl donor and could not be replaced by ATP plus methionine.
Fuesler
T P
TP
Department of Botany, University of California, Davis, California 95616.
Hanamoto
C M
CM
Castelfranco
P A
PA