Stabilization vs. degradation of Staphylococcus aureus metalloproteinase.
Purified Staphylococcus aureus metalloproteinase contains trace amounts of a serine proteinase which rapidly degrades the metalloproteinase when EDTA is present. However, no degradation occurs when Ca2+ is added or if the serine proteinase is removed by immunoaffinity chromatography. Selective chelation of Zn2+ by o-phenanthroline, which reversibly inactivates the metalloproteinase, does not result in the degradation of the apometalloproteinase, even with excess of serine proteinase. These data are interpreted as follows: EDTA chelates enzyme-bound Ca2+ and Zn2+, causing irreversible inactivation as well as a conformational change in the metal-free protein. This allows proteolysis by the contaminating serine proteinase and explains why the metalloproteinase purified from serine proteinase-deficient strains of S. aureus was previously thought to be stable to autolysis.
Potempa
J
J
Department of Microbiology and Immunology, Jagiellonian University, Kraków, Poland.
Porwit-Bobr
Z
Z
Travis
J
J
D002118:Calcium / Q000378:metabolism / Q000494:pharmacology; D002846:Chromatography, Affinity; D004355:Drug Stability; D004492:Edetic Acid / Q000494:pharmacology; D006863:Hydrogen-Ion Concentration; D008666:Metalloendopeptidases / Q000378:metabolism*; D010618:Phenanthrolines / Q000494:pharmacology; D011487:Protein Conformation / Q000187:drug effects; D012697:Serine Endopeptidases / Q000302:isolation & purification / Q000378:metabolism*; D013211:Staphylococcus aureus / Q000201:enzymology*; D015032:Zinc / Q000378:metabolism
D010618:Phenanthrolines; D004492:Edetic Acid; D012697:Serine Endopeptidases; D008666:Metalloendopeptidases; D015032:Zinc; D002118:Calcium; C025205:1,10-phenanthroline