Interaction between ferredoxin and ferredoxin-NADP reductase from chloroplasts

The photochemical reduction of pyridine nucleotides in isolated chloroplasts was shown to proceed via ferredoxin and ferredoxin-NADP reductase (Shin et, al., 1963. The latter enzyme is a flavoprotein which can also mediate the transfer of electrons in reverse, from NADPH to ferredoxin (Lazzarini and San Pietro, 1962), or to other acceptors such as: dyes (Avron and Jagendorf, 1956), NAD (Keister et, al., 1960) and chloroplast cytochrome f, (Zanetti and Forti, 1966). This communication reports observations indicating that ferredoxin inhibits several activities of the flavoprotein and forms a complex with it.