Studies on the heme and H2-uptake reaction from Azotobacter vinelandii bacterial ferritin

Autor: Xiang Chen, Can-He Chen, He-Qing Huang, Zhong Chen, Feng-Zhang Zhang, Qing-Mei Lin
Rok vydání: 1999
Předmět:
Zdroj: Bioelectrochemistry and Bioenergetics. 48:87-93
ISSN: 0302-4598
DOI: 10.1016/s0302-4598(98)00215-3
Popis: Bacterial ferritin of Azotobacter vinelandii (AvBF) is directly able to pick electrons up for iron release from or transfer them for storage to a platinum electrode in the absence of mediator or other reducer. The ferritin containing the structure of heme-Co2+ in part shows weakened activity to electrode and decreases the rate of iron release greatly. A reversible reduction process of the ferritin is observed by the spectral change regularly ranging from 310 to 260 nm under mixed gases containing 98% H2 and 2% to O2. The activity of nitrogen fixation from the whole cell of A. vinelandii increases greatly by H2 reduction with potentials ranging from -397 to -425 mV vs. NHE, indicating two important roles of H2-uptake reaction of the ferritin in increasing activity of nitrogen fixation and in supplying iron to synthesize nitrogenase.
Databáze: OpenAIRE