title: Purification, N-terminal amino acid sequence and properties of hydroxymethylbilane synthase (porphobilinogen deaminase) from Escherichia coli.
abstract: Hydroxymethylbilane synthase (porphobilinogen deaminase) was purified to apparent homogeneity from Escherichia coli. The enzyme is a monomer of Mr approx. 40,000. The Km for porphobilinogen and relative Vmax. values have been obtained at various pH values over the range 6.2-8.8, enabling pK values for ionizable groups important for activity to be determined. The N-terminal amino acid sequence is presented.
mesh_terms: D000595:Amino Acid Sequence; D000642:Ammonia-Lyases / Q000302:isolation & purification*; D004591:Electrophoresis, Polyacrylamide Gel; D004926:Escherichia coli / Q000201:enzymology*; D006863:Hydrogen-Ion Concentration; D011163:Hydroxymethylbilane Synthase / Q000302:isolation & purification*; D007700:Kinetics; D008970:Molecular Weight
chemical_list: D011163:Hydroxymethylbilane Synthase; D000642:Ammonia-Lyases