Chemical Basis for Deuterium Labeling of Fat and NADPH.

ABSTRACT: Much understanding of metabolism is based on monitoring chemical reactions in cells with isotope tracers. For this purpose, ¹³C is well suited due to its stable incorporation into biomolecules and minimal kinetic isotope effect. For redox reactions, deuterium tracing can provide additional information. To date, studies examining NADPH production with deuterated carbon sources have failed to account for roughly half of NADPH's redox active hydrogen. We show the missing hydrogen is the result of enzyme-catalyzed H-D exchange between water and NADPH. Though isolated NADPH does not undergo H-D exchange with water, such exchange is catalyzed by Flavin enzymes and occurs rapidly in cells. Correction for H-D exchange is required for accurate assessment of biological sources of NADPH's

SUBMITTER: Zhang Z 

PROVIDER: S-EPMC5748894 | biostudies-literature | 2017 Oct

REPOSITORIES: biostudies-literature