Greifenhagen U, Frolov A, Hoffmann R. Oxidative degradation of N(ε)-fructosylamine-substituted peptides in heated aqueous systems.
Amino Acids 2015;
47:1065-76. [PMID:
25712730 DOI:
10.1007/s00726-015-1940-2]
[Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2014] [Accepted: 02/11/2015] [Indexed: 10/23/2022]
Abstract
Glycation, or non-enzymatic glycosylation, is a common protein modification formed by reactions between reducing sugars (i.e. aldoses and ketoses) with protein amino groups. Resulting Amadori and Heyns compounds, respectively, can be oxidatively degraded yielding a structurally heterogeneous group of advanced glycation end-products. We have studied this process in aqueous conditions at 95 °C in terms of appearing products and their formation kinetics in the presence or absence of reactive oxygen species (ROS)-generating systems (iron(II) sulfate). RP-HPLC-ESI-MS revealed 20 products, 12 of which were confirmed after synthesis by identical retention times and fragmentation patterns. These products accumulated during the incubation period of 4 h (N(ε)-carboxymethyl-, N(ε)-formyl- and N(ε)-methyl lysine) or appeared intermediately (2-aminoadipic semialdehyde, N(ε)-ethanalyl lysine). Acidic and basic amino acid residues near the glycation site and elevated ROS levels in the reaction mixture had significant effects on both product formation and degradation kinetics.
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