title: Effect of calcium binding on conformational changes of staphylococcal metalloproteinase measured by means of intrinsic protein fluorescence.
abstract: The removal by EDTA of Ca2+ from the two-tryptophan-containing metalloproteinase isolated from Staphylococcus aureus leads to an increase in its intrinsic fluorescence intensity. Based on acrylamide fluorescence quenching results, analyzed by the non-linear least-squares method, we have shown that this protein molecule undergoes irreversible conformational change upon removal of Ca2+, which include the exposure to the solvent of buried tryptophan residues. Steady-state fluorescence anisotropy measurements indicate that the loss of Ca2+ leads to a significant increase in internal mobility of previously buried tryptophan residues.
mesh_terms: D020106:Acrylamide; D000178:Acrylamides / Q000494:pharmacology; D002118:Calcium / Q000378:metabolism*; D004492:Edetic Acid / Q000494:pharmacology; D010450:Endopeptidases / Q000378:metabolism*; D005453:Fluorescence; D008666:Metalloendopeptidases; D011487:Protein Conformation / Q000187:drug effects; D013050:Spectrometry, Fluorescence; D013211:Staphylococcus aureus / Q000201:enzymology*
chemical_list: D000178:Acrylamides; D020106:Acrylamide; D004492:Edetic Acid; D010450:Endopeptidases; D008666:Metalloendopeptidases; D002118:Calcium