Inactivation of human salivary glutathione transferase P1-1 by hypothiocyanite: a post-translational control system in search of a role.

ABSTRACT: Glutathione transferases (GSTs) are a superfamily of detoxifying enzymes over-expressed in tumor tissues and tentatively proposed as biomarkers for localizing and monitoring injury of specific tissues. Only scarce and contradictory reports exist about the presence and the level of these enzymes in human saliva. This study shows that GSTP1-1 is the most abundant salivary GST isoenzyme, mainly coming from salivary glands. Surprisingly, its activity is completely obscured by the presence of a strong oxidizing agent in saliva that causes a fast and complete, but reversible, inactivation. Although salivary α-defensins are also able to inhibit the enzyme causing a peculiar half-site inactivation, a number of approaches (mass spectrometry, site directed mutagenesis, chromatographic and spectropho

SUBMITTER: Fabrini R 

PROVIDER: S-EPMC4231102 | biostudies-literature | 2014

REPOSITORIES: biostudies-literature