Protein carbonylation: molecular mechanisms, biological implications, and analytical approaches.

Proteins are oxidatively modified by a large number of reactive species including reactive oxygen species, lipid peroxidation-derived aldehydes, and reducing sugars. Among divergent oxidative modifications, the introduction of carbonyl groups such as aldehyde, ketone, and lactam into the amino acid side chains of proteins is a major hallmark for oxidative damage to proteins, and is termed "protein carbonylation". Detection and quantification of protein carbonyls are commonly performed to determine the level of oxidative stress in the context of cellular damage, aging, and several age-related disorders. This review focuses on the molecular mechanisms and biological implications of protein carbonylation, and also presents current analytical approaches for determining and characterizing carbonylated proteins.