Issue Archive

Ferricyanide reductase in plasma membrane of maize roots

Chen Jia, Wang Jianhua

College of Biological Sciences, Beijing Agricultural University. Beijing

Abstract

Marked activity of ferricyanide reductase (FCR), an enzyme catalyzing the reduction of ferricyanide using NADH(or NADPH)as the electron donor, accompanied by transmembrane proton transport has been found in plasma membrane from maize roots. The △#mu#H~(+) formed by transmembrane proton transport in the redox reaction was found to be independent of ATP and not affected by vanadate, an inhibitor of H~(+)-ATPase. The latent activity of FCR showed that the enzyme had more suitable binding site(s) for the substrate on the cytoplasmic side of PM. The K_(m)of FCR for ferricyanide was found to be 70 #mu#mol L~(-1), and its K_(max) 2.1 #mu#mol mg~(-1) protein min~(-1). (with a concentration of NADH of 0.1 mmol L~(-1). The K_(m)for NADH was found to be 42 #mu#molL~(-1) and the K_(max) 1.84#mu#mol mg~(-1) proteim min~(-1)(with a concentration of ferricyanide of 0.25 mmol L~(-1)). The optimum pH of FCR was found to be 6.5. All Kinds of cations (Mg~(2+), Mn~(2+), Ca~(2+), K~(+)and Na~(+))had stimulative effect on ferricyanide reductase reductase activity, which was therefore nonspecific.

Key words: Ferricyanide reductase;Plasma membrane;Oxidation-reduction system;Trans-membrane proton transport;Maize root

Received: 　　Accepted:

Corresponding author: 　　E-mail:

Citing This Article：

Chen Jia, Wang Jianhua. Ferricyanide reductase in plasma membrane of maize roots. Acta Physiol Sin 1994; 46 (1): (in Chinese with English abstract).