Observation of holoprotein molecular ions of several ferredoxins by electrospray-ionization-mass spectrometry.
Several ferredoxins containing [4Fe-4S] or [2Fe-2S] active sites have been analyzed by electrospray-ionization-mass spectrometry. For these acidic proteins, low pH conditions must be implemented in order to ensure strong signals in positive-ionization mode. Under such conditions the iron-sulfur active sites were lost in most cases. In contrast, the holoproteins were preserved under negative-ionization mode conditions: they were weakly but sufficiently ionized and information about their cofactor content could be obtained. The experimental conditions set up here should provide a useful basis for the detailed characterization of more complex iron-sulfur proteins.
Pétillot
Y
Y
Laboratoire de Spectrométrie de Masse des Protéines, Institute de Biologie Structurale (CEA-CNRS), Grenoble, France.
Forest
E
E
Meyer
J
J
Moulis
J M
JM
D005288:Ferredoxins / Q000737:chemistry*; D013058:Mass Spectrometry / Q000379:methods*
D005288:Ferredoxins