Properties of chicken erythrocyte delta-aminolevulinate synthase.
A procedure is described for preparing a fraction highly enriched for chicken blood delta-aminolevulinate synthase (ALA-S) using animals recovering from acetylphenylhydrazine-induced anemia. 1. Blood cells collected from chickens recovering from anemia were disrupted by nitrogen cavitation, and the mitochondrial fraction was prepared from the cell homogenates. ALA-S was released then from mitochondria by sonication and isolated by a procedure involving gel filtration chromatography on Sephadex G-150, fractionation with ammonium sulfate, ion exchange chromatography on DEAE-Sephacel, and preparative isoelectric focusing. 2. Electrophoretic analyses under denaturing conditions indicated that the final ALA-S preparation was particularly enriched from a 62,200 Da polypeptide. The enzyme eluted from Sephadex G-200 with an equivalent molecular weight of 115,000; this suggested that active ALA-S was a dimer. 3. ALA-S was most active in the pH range of 7.0-8.0, with an apparent KM of 13 microM for succinyl-CoA and of 4.0 mM for glycine. The activity was inhibited 50% by 30 microM hemin.
Ades
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Department of Zoology, University of Maryland, College Park 20742.
Friedland
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D000624:5-Aminolevulinate Synthetase / Q000097:blood*; D000740:Anemia / Q000139:chemically induced; D000818:Animals; D002458:Cell Fractionation; D002645:Chickens; D004912:Erythrocytes / Q000201:enzymology*; D006863:Hydrogen-Ion Concentration; D007525:Isoelectric Focusing; D008970:Molecular Weight; D010659:Phenylhydrazines
D010659:Phenylhydrazines; C006384:N(1)-acetylphenylhydrazine; D000624:5-Aminolevulinate Synthetase