Fig. 3.

Identification of oxidized proteins. Aldehyde groups can be identified using enzymatic methods that rely on chemical derivatization of carbonyls with hydrazine, such as DNPH, biotin‐hydrazide, and hydrazides coupled to fluorescent molecules. Aldehyde groups can also be identified using amino acid analyzers, such as ATR‐FTIR and MS, with or without previous chemical derivatization. Oxidation can also be monitored by analyzing H₂0₂, one of the products of the reaction that is generated from the reoxidation of an internal cofactor; this compound can be analyzed with fluorometric assays. Finally, and considering that aldehyde groups are highly reactive, modification‐specific antibodies can be developed for the primary alcohol in the oxidation reaction and used as a readout of the final aldehyde.