Method for determining thioredoxin reductase activity

摘要

The present invention provides a method for measuring the activity of thioredoxin reductase in mammalian cells by contacting the cells in vivo or in vitro with a quaternary ammonium salt spin-labelled with a stable nitroxide free radical, and measuring the rate of reduction of the uncomplexed nitroxide free radical at the cell surface by electron spin resonance. This rate of reduction provides a measure of thioredoxin reductase activity at the surface of the cells.