Peroxidase-Catalyzed and Photo-Oxidation of Tryptophan Results in Distinct Isomeric Tryptophan Dimers.

ABSTRACT: Heme peroxidases, including horseradish peroxidase (HRP), catalyze the oxidation of a wide variety of substrates by hydrogen peroxide (H₂O₂) via the peroxidase cycle of these enzymes. Oxidation of free tryptophan (Trp) by HRP/H₂O₂ has been previously reported, but the formation of tryptophan dimers (di-Trp), which are biologically relevant, has not been studied. Here, we report on di-Trp production arising from oxidation of free Trp, at pH 5.5 and 9.2, by HRP/H₂O₂, as determined by liquid chromatography-mass spectrometry (LC-MS/MS) and selected reaction monitoring (SRM). These data were compared with those from riboflavin-sensitized photo-oxidation, and the products were rationalized by in silico studies. Incubation o

SUBMITTER: Morales M 

PROVIDER: S-EPMC12547766 | biostudies-literature | 2025 Oct

REPOSITORIES: biostudies-literature