title: Influence of EDTA and metal ions on a metalloproteinase from Pseudomonas fluorescens biotype I.
abstract: The inactivation of a metalloproteinase from Pseudomonas fluorescens Biotype I with EDTA was investigated at 22 degrees C and 37 degrees C. At 22 degrees C proteolytic activity decreases linearly with time and an inactive apoenzyme is obtained by dialysis. Proteolytic activity can be restored with several metal-ions, Ca2+, Zn2+, Mg2+, Sr2+ and co2+ give the best results. Activity and substrate specificity are influenced by the metal-ions. Reactivation depends on the concentration of the metal-ions, optimum concentration is 1 mM for Ca2+ and 50 microM for Zn2+. The isoelectric point of the apoenzyme is around 8.0, this is about 0.3 pH-units lower than the isoelectric point of the native proteinase. At 37 degrees C inactivation follows first order kinetics and is irreversible because of autolysis as shown by a gel filtration-experiment.
mesh_terms: D001051:Apoenzymes / Q000378:metabolism; D004492:Edetic Acid / Q000494:pharmacology; D010450:Endopeptidases / Q000378:metabolism; D004793:Enzyme Reactivators; D008666:Metalloendopeptidases; D008670:Metals / Q000494:pharmacology; D011480:Protease Inhibitors; D011551:Pseudomonas fluorescens / Q000201:enzymology*
chemical_list: D001051:Apoenzymes; D004793:Enzyme Reactivators; D008670:Metals; D011480:Protease Inhibitors; D004492:Edetic Acid; D010450:Endopeptidases; D008666:Metalloendopeptidases