Wydział Chemii

Teresa Kowalik-Jankowska

Anna Rajewska

Elżbieta Jankowska

K. Wiśniewska

Z. Grzonka

2006

Journal of Inorganic Biochemistry

100

1623-1631

10.1016/j.jinorgbio.2006.05.010

Naukowa

Angielski

Artykuł

Reactive oxygen species (ROS) may provide the covalent modifications of amino acid residues in proteins, formation of protein–protein cross-linkages, and oxidation of the protein backbone resulting in protein fragmentation. In an attempt to elucidate the products of the copper(II)-catalyzed oxidation of the (1–17), (1–28), (1–39) and (1–39)(A30P) fragments of α-synuclein, the high performance liquid chromatography (HPLC) and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI–TOF MS) methods and Cu(II) /hydrogen peroxide as a model oxidizing system were employed. Peptide solution (0.50 mM) was incubated at 37 °C for 24 h with metal:peptide:hydrogen peroxide molar ratio 1:1:4 in phosphate buffer, pH 7.4. Oxidation targets for all peptide studied are the methionine residues (M¹, M⁵). Incubation 24 h of the (1–28), (1–39) and (1–39)(A30P) fragments in aerobic conditions lead to the oxidation of one methionine residue to methionine sulfoxide. Reaction of hydrogen peroxide with all fragments of α-synuclein resulted in oxidation of two methionine residues (M¹, M⁵) to methionine sulfoxides. For the Cu(II):peptide:hydrogen peroxide 1:1:4 molar ratio systems the further oxidation of methionine residues to sulfone was observed. The cleavage of the peptide bond M¹–D² for all peptides studied was observed as metal binding residues. For the (1–39) and (1–39)(A30P) fragments of α-synuclein the molecular ions with lower molecular masses (A¹¹–Y³⁹, E¹³–Y³⁹) were also detected.

α-Synuclein, Metal-catalyzed oxidation, Copper(II) complexes, Products of oxidation, MALDI–TOF MS

https://doi.org/10.1016/j.jinorgbio.2006.05.010

http://www.elsevier.com