Chymotrypsin digestion analysis of glycyl radical and B12-dependent radical enzymes indicates common substrate-induced structural shifts.

ABSTRACT: Radical enzymes, including glycyl radical enzymes (GREs) and B12-dependent enzymes, catalyze a wide range of biochemical transformations through radical-based mechanisms. An unusual property-conditional resistance to chymotrypsin digestion-has previously been reported for two GREs. However, whether this feature is broadly conserved among related radical enzymes and what factors trigger it has remained unclear. In this study, we investigated five radical enzymes: four GREs and one B12-dependent diol dehydratase. Proteolytic assays demonstrated that substrate binding significantly enhances resistance to chymotrypsin degradation, suggesting a conserved conformational shift from an open, protease-sensitive state to a closed, protease-resistant form. X-ray crystallographic analysis of a GRE-typ

SUBMITTER: Mitjkova E 

PROVIDER: S-EPMC12756279 | biostudies-literature | 2025 Dec

REPOSITORIES: biostudies-literature