• Fulltext

       

        Click here to view fulltext PDF


      Permanent link:
      https://www.ias.ac.in/article/fulltext/jbsc/017/02/0183-0192

    • Keywords

       

      C4 enzymes; ferredoxin-thioredoxin system; photoactivation; photosystem I

    • Abstract

       

      Light, besides initiating primary photochemical processes, alters the redox state of soluble components in chloroplast. The present review attempts to cover the mechanism of reductive photoactivation of enzymes of photosynthetic carbon reduction cycle using key enzymes as examples. The reduced soluble components — ferredoxin, thioredoxin and NADPH, in turn, cause the reduction of disulphides to dithiols of chloroplastic enzymes. NADP-malate dehydrogenase is subject to activation by light through changes in NADPH/NADP. The key enzyme of C4 photosynthesis-PEP carboxylase, though cytosolic, has been shown to be activated by disulphide/sulphhydryl interconversion by reductants generated in light through chloroplast electron transport flow. PyruvatePi dikinase activity is controlled by the adenylate energy charge. It remains unclear how light controls the activation of cytosolic enzymes.

    • Author Affiliations

       

      V Maheshwari1 U Dwivedi1 R Bhardwaj1 Rashmi Mishra1

      1. School of Biochemistry, Devi Ahilya University, Khandwa Road, Indore - 452 001, India
    • Dates

       
  • Journal of Biosciences | News

© 2017-2019 Indian Academy of Sciences, Bengaluru.