Related Experiment Video
Updated: Aug 21, 2026

Simultaneous Measurement of Superoxide/Hydrogen Peroxide and NADH Production by Flavin-containing Mitochondrial Dehydrogenases
Published on: February 24, 2018
A novel NADPH:(bound) NADP+ reductase and NADH:(bound) NADP+ transhydrogenase function in bovine liver catalase
Gian F Gaetani1, Anna M Ferraris, Paola Sanna
1Division of Hematological Oncology, Istituto Nazionale per la Ricerca sul Cancro and Dipartimento di Medicina Interna, University of Genoa, 16132 Genoa, Italy.
Abstract:
Many catalases have the shared property of containing bound NADPH and being susceptible to inactivation by their own substrate, H2O2. The presence of additional (unbound) NADPH effectively prevents bovine liver and human erythrocytic catalase from becoming compound II, the reversibly inactivated state of catalase, and NADP+ is known to be generated in the process. The function of the bound NADPH, which is tightly bound in bovine liver catalase, has been unknown. The present study with bovine liver catalase and [14C]NADPH and [14C]NADH revealed that unbound NADPH or NADH are substrates for an internal reductase and transhydrogenase reaction respectively; the unbound NADPH or NADH cause tightly bound NADP+ to become NADPH without becoming tightly bound themselves. This and other results provide insight into the function of tightly bound NADPH.
Related Concept Videos
Role of Reduced Coenzymes NADH and FADH₂
Electron Transport Chain: Complex I and II
ROS generation is regulated and maintained at moderate levels necessary...
Electron Transport Chain: Complex III and IV
Redox Reactions
Protein Import into the Peroxisomes
Peroxisomal Protein Import:
Peroxisomes lack the genetic machinery required to code for their own proteins. Hence, most peroxisomal membrane, lumenal and transmembrane proteins are synthesized in the cytoplasm or ER and transported to the peroxisome...
Oxidation of Phenols to Quinones
o-hydroxy phenols are oxidized to o-quinones and p-hydroxy phenols to p-quinones. Such redox reactions involve the transfer of two electrons and two protons. The reversible redox property is crucial in...

