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Superoxide radicals can act synergistically with hypochlorite to induce damage to proteins
Author(s) -
Hawkins Clare L.,
Rees Martin D.,
Davies Michael J.
Publication year - 2002
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/s0014-5793(01)03226-4
Subject(s) - chloramine , chemistry , radical , superoxide , hypochlorite , myeloperoxidase , hypochlorous acid , reactive oxygen species , biochemistry , superoxide dismutase , photochemistry , enzyme , organic chemistry , inflammation , chlorine , immunology , biology
Activated phagocytes generate both superoxide radicals via a respiratory burst, and HOCl via the concurrent release of the haem enzyme myeloperoxidase. Amine and amide functions on proteins and carbohydrates are major targets for HOCl, generating chloramines (RNHCl) and chloramides (RC(O)NClR′), which can accumulate to high concentrations (>100 μM). Here we show that superoxide radicals catalyse the decomposition of chloramines and chloramides to reactive nitrogen‐centred radicals, and increase the extent of protein fragmentation compared to that observed with either superoxide radicals or HOCl, alone. This synergistic action may be of significance at sites of inflammation, where both superoxide radicals and chloramines/chloramides are formed simultaneously.