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Novel biological function of sialic acid ( N ‐acetylneuraminic acid) as a hydrogen peroxide scavenger
Author(s) -
Iijima Ryosuke,
Takahashi Hideyo,
Namme Rie,
Ikegami Shiro,
Yamazaki Masatoshi
Publication year - 2004
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(04)00164-4
Subject(s) - hydrogen peroxide , chemistry , neuraminidase , sialic acid , n acetylneuraminic acid , scavenger , biochemistry , reactive oxygen species , enzyme , chlorine , oxidative phosphorylation , stereochemistry , radical , organic chemistry
We have found that N ‐acetylneuraminic acid (NANA) consumes toxic hydrogen peroxide (H 2 O 2 ) under physiological conditions. Close investigation of this finding revealed that NANA was oxidized by an equimolar amount of H 2 O 2 to provide its decarboxylated product, 4‐(acetylamino)‐2,4‐dideoxy‐ D ‐glycero‐ D ‐galacto‐octonic acid (ADOA). To date, there have been little data on this reaction, and its physiological significance has not been discussed. Examining the detoxification of H 2 O 2 in cultured cells with NANA, we were able to confirm that the cell death caused by H 2 O 2 was suppressed by NANA in a dose‐dependent manner. These results revealed a novel role for NANA as a reactive oxygen scavenger. It is known that terminal NANA residues are removed by neuraminidase and that free NANA molecules are recycled or degraded by enzymes. We propose that released monomeric NANA is the potent defense molecule against oxidative damage.