Biosynthesis of Δ-aminolevulinate in greening barley leaves IV. Isolation of three soluble enzymes required for the conversion of glutamate to Δ-aminolevulinate
Conversion of glutamate into glutamate-1-semialdehyde in the presence of ATP, Mg2+ and NADPH requires at least two proteins, one binding to heme-Sepharose and one binding to Blue Sepharose.
Glutamate-1-semialdehyde is converted into δ-aminolevulinate by glutamate-1-semialdehyde aminotransferase, which is not retained on the affinity columns.
The run-off protein fraction also contains δ-aminolevulinate dehydratase and porphobilinogen deaminase.
The heme-Sepharose bound protein(s) probably converts glutamate to glutamate-1-phosphate in the presence of ATP and Mg2+ and the Blue-Sepharose bound protein(s), glutamate-1-phosphate to glutamate-1-semialdehyde, in the presence of NADPH.