The magnesium-protoporphyrin IX (oxidative) cyclase system. Studies on the mechanism and specificity of the reaction sequence.

Mg-protoporphyrin IX monomethyl ester cyclase activity was assayed in isolated developing cucumber (Cucumis sativus L. var. Beit Alpha) chloroplasts [Chereskin, Wong & Castelfranco (1982) Plant Physiol.

Separation of monovinyl and divinyl protochlorophyllides and chlorophyllides from etiolated and phototransformed cucumber cotyledons.

A method was developed to separate the monovinyl and divinyl forms of protochlorophyllide and chlorophyllide by high pressure liquid chromatography using a silicic acid column coated with dodecyl residues and a moving phase containing the lipophilic cation, tetrabutyl ammonium. The solvent was 70% methyl alcohol containing varying amounts of methyl ethyl ketone. The separation was carried out at 0 degrees C.

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.