mARC1 Is the Main Contributor to Metabolic Reduction of -Hydroxyurea.

-Hydroxyurea has been known since the 1960s as an antiproliferative drug and is used both in oncology and for treatment of hematological disorders such as sickle cell anemia where very high daily doses are administered. It is assumed that the cellular effect of -hydroxyurea is caused by inhibition of ribonucleotide reductase, while alternative mechanisms, e.g.

Reduction of Hydrogen Peroxide by Human Mitochondrial Amidoxime Reducing Component Enzymes.

The mitochondrial amidoxime reducing component (mARC) is a human molybdoenzyme known to catalyze the reduction of various -oxygenated substrates. The physiological function of mARC enzymes, however, remains unknown. In this study, we examine the reduction of hydrogen peroxide (HO) by the human mARC1 and mARC2 enzymes.

New Design of an Activity Assay Suitable for High-Throughput Screening of Substrates and Inhibitors of the Mitochondrial Amidoxime Reducing Component (mARC).

The mitochondrial amidoxime-reducing component (mARC) is one of the simplest molybdenum-containing enzymes. mARC is among a few known reducing enzymes playing an important role in drug metabolism in mammals. Here, an assay based on the fluorescence of NADH is reported for the rapid detection of substrates and potential inhibitors of mARC.