Isolation of the mature subunit of delta-aminolaevulinate synthase from embryonic chick liver.
We presented evidence indicating that the established procedure for purifying delta-aminolaevulinate (ALA) synthase from embryonic-chick liver yielded an enzyme with a partially degraded subunit of molecular weight 51000 [Ades & Harpe (1981) J. Biol. Chem. 256, 9329-9333]. We now report the purification from livers of porphyric embryos of a preparation of ALA synthase which consisted primarily of a 63000-Da polypeptide and a component migrating as a smear of polypeptides with a minimum molecular weight of 52 000. Neither component could be recovered from liver mitochondria of normal embryos, where the amounts of ALA synthase were relatively low. The 52 000-Da component had been established to be the partially degraded subunit of the enzyme. Peptide-mapping analyses indicated that the 63 000- and the 52 000-Da components possessed significant structural homologies, and it was concluded that the 63 000-Da polypeptide represented the mature subunit of ALA synthase.
D000624:5-Aminolevulinate Synthetase / Q000302:isolation & purification*; D000818:Animals; D002642:Chick Embryo; D002846:Chromatography, Affinity; D004591:Electrophoresis, Polyacrylamide Gel; D007525:Isoelectric Focusing; D008930:Mitochondria, Liver / Q000201:enzymology*; D008970:Molecular Weight; D010446:Peptide Fragments / Q000032:analysis
D010446:Peptide Fragments; D000624:5-Aminolevulinate Synthetase