β-Carotene alleviates substrate inhibition caused by asymmetric cooperativity.

ABSTRACT: Enzymes are essential catalysts in biological systems. Substrate inhibition, once dismissed, is now observed in 20% of enzymes¹ and is attributed to the formation of an unproductive enzyme-substrate complex, with no structural evidence of unproductivity provided to date^1-6. This study uncovers the molecular mechanism of substrate inhibition in tobacco glucosyltransferase NbUGT72AY1, which transfers glucose to phenols for plant protection. The peculiarity that β-carotene strongly attenuates the substrate inhibition of NbUGT72AY1, despite being a competitive inhibitor, allows to determine the conformational changes that occur during substrate binding in both active and substrate-inhibited complexes. Crystallography reveals structurally different ternary enzyme-substrate

SUBMITTER: Liao J 

PROVIDER: S-EPMC11954892 | biostudies-literature | 2025 Mar

REPOSITORIES: biostudies-literature