Partridge C D, Yates M G
Biochem J. 1982 Apr 15;204(1):339-44. doi: 10.1042/bj2040339.
The chelating agents EDTA, o-phenanthroline, nitrilotriacetic acid (NTA), ethylenediamine-bis(o-hydroxyphenylacetic acid) (EDDA) or dimethylglyoxime prevented the expression of hydrogenase activity in batch cultures of nitrogen-fixing Azotobacter chroococcum, but did not inhibit preformed enzyme. The inhibition was reversed either by adding a mixture of trace elements (Cu2+, Mn2+, Zn2+, Co2+) or Ni2+ or, to a lesser degree, Co2+ alone. Ni2+ or Ni2+ + Fe2+ also enhanced the rate of hydrogenase derepression in A. chroococcum in the absence of any added chelator, if the medium was first extracted with 8-hydroxyquinoline. A. chroococcum accumulated 63Ni2+ by an energy-independent mechanism. Both, Ni2+ uptake and hydrogenase synthesis were equally inhibited by either NTA, EDTA, EDDA or dimethylglyoxime. The evidence suggests a role for Ni2+ in hydrogenase synthesis.
螯合剂乙二胺四乙酸（EDTA）、邻菲罗啉、次氮基三乙酸（NTA）、乙二胺双（邻羟基苯乙酸）（EDDA）或丁二酮肟可抑制固氮的褐球固氮菌分批培养物中氢化酶活性的表达，但不抑制已形成的酶。通过添加微量元素混合物（Cu2+、Mn2+、Zn2+、Co2+）或Ni2+，或在较小程度上单独添加Co2+，可逆转这种抑制作用。如果先用8-羟基喹啉萃取培养基，那么在不添加任何螯合剂的情况下，Ni2+或Ni2+ + Fe2+也可提高褐球固氮菌中氢化酶去阻遏的速率。褐球固氮菌通过能量非依赖机制积累63Ni2+。NTA、EDTA、EDDA或丁二酮肟均可同样抑制Ni2+的摄取和氢化酶的合成。证据表明Ni2+在氢化酶合成中起作用。
