Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
2007648 | Peptides | 2007 | 8 Pages |
Abstract
In some type-3 copper proteins (molluskan hemocyanin, catechol oxidase and fungal tyrosinase) one of the histidine residues, liganding the CuA atom of the dinuclear copper active site, is covalently linked to a cysteine residue by a thioether bridge. The purpose of this study was to disclose the function of this bridge. Mass spectral analysis of a peptide, isolated from Rapana thomasiana (gastropodan mollusk) hemocyanin, indicated a stabilization of the peptide structure in the region of the bridge. Molecular modeling of three thioether containing type-3 copper proteins using the dead-end elimination method showed that the concerned histidine would be very flexible if not linked to the cysteine. Also, the side chain orientation of the histidine is rather exceptional, as evidenced by statistical data from the protein databank. It is suggested that the role of the bridge is to fix the histidine in an orientation that is optimal for coordination of the CuA atom.
Keywords
Rapana thomasianaESIFPLCRTHPDBDEETFA4-Vinylpyridinem/zElectrospray Ionization Mass SpectrometryTrifluoroacetic acidProtein Databankdead-end eliminationfast protein liquid chromatographyMass spectrometrymass to charge ratioHemocyaninfunctional unitHigh pressure liquid chromatographyHPLCelectrospray ionization
Related Topics
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Biochemistry, Genetics and Molecular Biology
Biochemistry
Authors
Constant Gielens, Krassimira Idakieva, Marc De Maeyer, Viviane Van den Bergh, Nurul Islam Siddiqui, Frans Compernolle,