Abstract
The effect of calcium ions has been studied on three different isoforms of thioredoxin reductase. The cytosolic (TrxR1), mitochondrial (TrxR2), and the Escherichia coli enzymes were examined and compared. In our condition, TrxR1 appears extremely sensitive to Ca 2+ showing an IC 50 of about 160 nM, while Ca 2+ exerts only a weak inhibitory effect on the mitochondrial isoform. The thioredoxin reductase purified from E. coli is almost completely insensitive to calcium ions. Circular dichroism analysis of highly purified mitochondrial and cytosolic thioredoxin reductases reveals that Ca 2+ induces conformational alterations that are particularly relevant only in the cytosolic isoform. These observations are discussed with reference to the physiological role and, in particular, to the regulatory functions of the thioredoxin system.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callMore From: Biochemical and Biophysical Research Communications
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
