Specific electrochemical nitration of horse heart myoglobin
UNSPECIFIED. (2001) Specific electrochemical nitration of horse heart myoglobin. ARCHIVES OF BIOCHEMISTRY AND BIOPHYSICS, 392 (2). pp. 169-179. ISSN 0003-9861Full text not available from this repository.
Earlier findings on electronitration of hen egg-white lysozyme demonstrated a product which was mononitrated at Tyr23, by ion-exchange chromatography, absorbance at 430 nm, dithionite reduction, and Edman sequencing of a nitrated proteolytic peptide. However, the whole protein was not sequenced; therefore, although the enzyme remained active upon nitration, reaction at other residues could not be completely eliminated. This study has now been extended to the redox protein myoglobin. We demonstrate the novel electronitration (electrooxidation in the presence of nitrite) of a specific tyrosine residue in horse heart myoglobin and also in apomyoglobin. Production of the yellow chromophore, 3-nitrotyrosine (3-NT), was apparent in apomyoglobin from A(430) but was masked in holomyoglobin by the Soret band. In both cases' the presence of 3-NT in the electronitrated samples was further indicated by the binding of antibody to 3-NT in Western blots. High-resolution electrospray ionization (ESI) Fourier transform ion cyclotron resonance (FTICR) mass spectrometry revealed a reaction product at [M + 45] (consistent with substitution of NO, for H), indicating that the nitration reaction is the only reaction occurring which gives rise to a change I. Ln mass in the electrooxidation. Fragmentation mass spectrometry identified the nitration site as Tyr103, with no nitration at Tyr146. The procedure may be useful in preparing model nitrated proteins for the study of disease mechanisms. (C) 2001 Academic Press.
|Item Type:||Journal Article|
|Subjects:||Q Science > QD Chemistry
Q Science > QH Natural history > QH301 Biology
|Journal or Publication Title:||ARCHIVES OF BIOCHEMISTRY AND BIOPHYSICS|
|Publisher:||ACADEMIC PRESS INC|
|Official Date:||15 August 2001|
|Number of Pages:||11|
|Page Range:||pp. 169-179|
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