Electrospray ionization mass spectrometry analysis of the apo- and metal-substituted forms of the Fur protein.
Fur has been purified and reconstituted with Co2+ and Mn2+. The ESI-MS spectra of the apoprotein as well as Mn-Fur and Co-Fur under acidic denaturating conditions showed the existence of two species of molecular mass 16,660 +/- 3 and 16,792 +/- 3 Da, which correspond, respectively, to the N-terminal methionine 'excised' or 'non-excised' forms of the monomer. This result proves the absence of any other post-translational modification or modification due to metal incorporation. On the other hand, under soft conditions, ESI spectra provided for the first time direct evidence for dimeric metal-containing forms in solution.
Michaud-Soret
I
I
Département de Recherche Fondamentale sur la Matière Condensée, (Unité de Recherche Associée au CNRS No. 1194), CEA-Grenoble, France. michaud@drfmc.ceng.cea.fr
Adrait
A
A
Jaquinod
M
M
Forest
E
E
Touati
D
D
Latour
J M
JM
D001059:Apoproteins / Q000737:chemistry*; D001426:Bacterial Proteins / Q000737:chemistry*; D003035:Cobalt; D007501:Iron; D008345:Manganese; D013058:Mass Spectrometry / Q000379:methods; D008715:Methionine; D008970:Molecular Weight; D011487:Protein Conformation; D011489:Protein Denaturation; D011499:Protein Processing, Post-Translational; D011994:Recombinant Proteins / Q000737:chemistry; D012097:Repressor Proteins / Q000737:chemistry*
D001059:Apoproteins; D001426:Bacterial Proteins; D011994:Recombinant Proteins; D012097:Repressor Proteins; C068477:ferric uptake regulating proteins, bacterial; D003035:Cobalt; D008345:Manganese; D008715:Methionine; D007501:Iron