Abstract
The nature and the role of eIF-2 phosphoprotein phosphatase in rabbit reticulocyte lysates have been examined. The eIF-2 phosphoprotein phosphatase is inhibited by a variety of divalent metal ions (Cd ++>Ag ++> Cu ++>Pb ++>Zn ++>Co ++>Sr ++>Mo ++) in lysates in situ . In addition, PPi, EDTA and NaF inhibit this enzyme. The eIF-2 phosphoprotein phosphatase is also inhibited by NaHSO 3 and Na 2S 2O 5. Na 2S 2O 5 is, however, more effective. Na 2S 2O 5 has been found to be a potent inhibitor of protein synthesis in lysates. This inhibition is associated with the phosphorylation of the 38,000-dalton subunit of initiation factor eIF-2. eIF-2 overcomes this inhibition. These findings suggest that under optimum conditions of protein synthesis the phosphorylation and dephosphorylation of eIF-2 are in a dynamic state of equilibrium in which dephosphorylation is favored. The inhibition of eIF-2 phosphoprotein phosphatase by Na 2S 2O 5 shifts this equilibrium in favor of eIF-2 phosphorylation, consequently, protein synthesis is inhibited. The sulfhydryl nature of eIF-2 phosphoprotein phosphatase has been established.
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.
