Tsopanakis A D, Bray R C, Smith B E
Biochem J. 1979 Aug 1;181(2):509-12. doi: 10.1042/bj1810509.
Both the protein components Kp1 and Kp2 of nitrogenase from Klebsiella pneumoniae were found to be stable in aq. 50% (v/v) ethylene glycol at +30 degrees C or below. At -20 degrees C in this medium their sensitivities to O2 were diminished somewhat. Though purification could be carried out at -20 degrees C, the product had the same specific activity and was obtained in the same yield as when the purification was carried out by standard procedures. This suggests that such procedures yield enzyme undamaged in the course of the purification by O2, thermal denaturation or proteolytic digestion.
已发现肺炎克雷伯菌固氮酶的蛋白质组分Kp1和Kp2在30℃或更低温度下的50%（v/v）乙二醇水溶液中是稳定的。在该介质中于-20℃时，它们对O2的敏感性有所降低。尽管纯化可以在-20℃下进行，但产物的比活性相同，且产率与通过标准程序进行纯化时相同。这表明这些程序产生的酶在纯化过程中未受到O2、热变性或蛋白水解消化的损害。
