Wong P P, Burris R H
Proc Natl Acad Sci U S A. 1972 Mar;69(3):672-5. doi: 10.1073/pnas.69.3.672.
The reduction of nitrogen, acetylene, azide, and cyanide at various oxygen concentrations by nitrogenase from Azotobacter vinelandii was measured with a well-defined system. Oxygen inhibited the reduction of each substrate uncompetitively. The inhibition constants (K(i)) were 0.014, 0.023, 0.008, and 0.003 atm of oxygen for reduction of nitrogen, acetylene, azide, and cyanide, respectively. The system used included ATP-generating components, subcellular particles from A. vinelandii with high nitrogenase specific activity, and illuminated spinach chloroplasts plus carriers to supply electrons. Oxygen did not affect the photochemical electron donating system, but it did inhibit nitrogenase-dependent ATP hydrolysis.
利用一个定义明确的系统，测定了在不同氧气浓度下，维涅兰德固氮菌的固氮酶对氮气、乙炔、叠氮化物和氰化物的还原作用。氧气以非竞争性方式抑制了每种底物的还原。对于氮气、乙炔、叠氮化物和氰化物的还原，抑制常数（K(i)）分别为0.014、0.023、0.008和0.003个大气压的氧气。所使用的系统包括ATP生成成分、具有高固氮酶比活性的维涅兰德固氮菌亚细胞颗粒，以及经光照的菠菜叶绿体加载体以提供电子。氧气不影响光化学电子供体系统，但确实抑制了依赖固氮酶的ATP水解。
