title: Aminopeptidase II from Bacillus stearothermophilus.
abstract: 1. The low molecular weight aminopeptidase (aminopeptidase II) from Bacillus stearothermophilus cells grown at 50 degrees C was purified to a homogeneous state. 2. Molecular weight determination by sodium dodecyl sulfate gel electrophoresis resulted in a value of 46 000 for the subunits. A molecular weight of 80 000-100 000 has been reported for the native enzyme. We therefore conclude that aminopeptidase II is a dimeric enzyme. 3. The amino-terminal sequence, the amino acid analysis and the subunit molecular weight of aminopeptidase II show no relationship to the corresponding data of aminopeptidase I. 4. Aminopeptidase II binds two Co2+ per subunit. The dissociation constants of these ions determined by binding studies and by kinetic analysis agree within experimental error.
mesh_terms: D000596:Amino Acids / Q000032:analysis; D000626:Aminopeptidases / Q000276:immunology / Q000302:isolation & purification / Q000378:metabolism; D003035:Cobalt / Q000494:pharmacology; D001411:Geobacillus stearothermophilus / Q000201:enzymology*; D046911:Macromolecular Substances; D008970:Molecular Weight; D011485:Protein Binding
chemical_list: D000596:Amino Acids; D046911:Macromolecular Substances; D003035:Cobalt; D000626:Aminopeptidases