title: Purification, crystallization, and molecular properties of aspartase from Pseudomonas fluorescens.
abstract: Aspartase [L-aspartate ammonia-lyase, EC 4.3.1.1] of Pseudomonas fluorescens was highly purified to homogeneity and crystallized. The purified enzyme sedimented as a monodisperse entity upon ultracentrifugation with a s0(20),w value of 8.6S. Upon polyacrylamide gel electrophoresis (PAGE), the enzyme migrated as a single band. The molecular weight of the native enzyme was 173,000 +/- 3,000, as determined by sedimentation equilibrium analysis, and that of the enzyme subunit was determined to be 50,000 +/- 1,500 by sodium dodecyl sulfate (SDS)-PAGE. Cross-linking experiments using dimethyl suberimidate followed by SDS-PAGE indicated that the native enzyme was composed of four subunits with identical molecular weight. The amino acid composition of the enzyme was determined.
mesh_terms: D000596:Amino Acids / Q000032:analysis; D000642:Ammonia-Lyases / Q000302:isolation & purification*; D001220:Aspartate Ammonia-Lyase / Q000302:isolation & purification*; D003460:Crystallization; D004120:Dimethyl Suberimidate / Q000494:pharmacology; D004591:Electrophoresis, Polyacrylamide Gel; D046911:Macromolecular Substances; D008970:Molecular Weight; D011551:Pseudomonas fluorescens / Q000201:enzymology*
chemical_list: D000596:Amino Acids; D046911:Macromolecular Substances; D004120:Dimethyl Suberimidate; D000642:Ammonia-Lyases; D001220:Aspartate Ammonia-Lyase