title: Purification and properties of human erythrocyte delta-amino-levulinic acid dehydratase (EC 4-2-1-24).
abstract: Human delta-aminolevulinic acid dehydratase (ALA-D) was purified 9 000-fold by salt precipitation, ion-exchange chromatography and gel filtration. These methods resulted into an electrophoretically and immunologically pure protein. The optimum pH of the enzyme is 6.6 and its Km with ALA : 4.8 X 10(-4) M. The enzymatic activity was increased by thiol-containing substances, such as dithiothreitol (DTT), which protect the -SH groups of the protein. Zinc, a portion of the enzyme molecule, was partly lost during the purification procedure; its addition enhances the enzymatic activity. Determination of molecular weights and electron microscopy study are in favor of an octameric structure.
mesh_terms: D000818:Animals; D000906:Antibodies; D002417:Cattle; D055598:Chemical Phenomena; D002621:Chemistry; D003429:Cross Reactions; D004912:Erythrocytes / Q000201:enzymology*; D006801:Humans; D008099:Liver / Q000201:enzymology; D008722:Methods; D008970:Molecular Weight; D000623:Porphobilinogen Synthase / Q000097:blood / Q000276:immunology / Q000302:isolation & purification*; D011487:Protein Conformation
chemical_list: D000906:Antibodies; D000623:Porphobilinogen Synthase