Department of Biology, Queen's University, Kingston, Ontario Canada K7L 3N6.
Plant Physiol. 1978 Jun;61(6):1037-9. doi: 10.1104/pp.61.6.1037.
Proplastids from developing castor bean (Ricinus communis) endosperm have a pyruvate kinase activity which is extremely unstable on isolation from the organelle. It can be stabilized by 20 mm 2-mercaptoethanol in 20% ethylene glycol. In contrast the soluble pyruvate kinase is stable at 60 C for 10 minutes. The two activities have different pH optima. The soluble and the proplastid activities are eluted from a diethylaminoethyl-Sephadex A-25 sievorptive column at different ionic strengths.
发育中的蓖麻种子(Ricinus communis)胚乳中的前质体具有丙酮酸激酶活性,这种活性在从细胞器中分离出来时极其不稳定。它可以通过 20%乙二醇中的 20mm 巯基乙醇稳定下来。相比之下,可溶性丙酮酸激酶在 60°C 下稳定 10 分钟。这两种活性具有不同的 pH 最佳值。可溶性和前质体活性在前质体中从 DEAE-葡聚糖 A-25 洗脱柱洗脱时在不同的离子强度下洗脱。