δ-Aminolevulinate synthase isozymes in the liver and erythroid cells of chicken

Antibodies raised against the purified chicken liver δ-aminolevulinate synthase showed a partial cross-reactivity with the chicken erythroid δ-aminolevulinate synthase. δ-Aminolevulinate synthase synthesized in vitro using polysomes from erythroid cells showed a subunit molecular weight of 55,000, whereas the enzyme synthesized in vitro using liver polysomes had a subunit molecular weight of 73,000. δ-Aminolevulinate synthase isolated from mitochondria of erythroid cells showed a molecular weight of 53,000, while the enzyme in liver mitochondria had a value of 65,000. These observations imply that the erythroid δ-aminolevulinate synthase differs from the hepatic enzyme.