- 作者: Shih-Long YAN, Chien-Chieng TSAY and Yung-Reui CHEN
- 中文摘要: Rice plants were treated with 50 .mu.M copper sulfate to induce the synthesis of phytochelatins by means of a series of enzymatic reactions, including that of photochelatin synthase. Phytochelatin synthase extracted from 3- week-old rice seedlings was purified through a series of steps including precipitation with ice-chilled acetone, QAE A-50 anion exchange column, Amicon XM-50 ultrafiltration and Polybuffer Exchange (PBE) 94 chromatofocusing. This enzyme had a molecular mass of about 100 kDa with an isoelectric point of 4.0. The temperature and pH optima of this enzyme were 55.degree.C and pH 7.5, respectively. The enzyme was thermal tolerable and unstable under refrigeration at 4 or -20.degree.C. Cadmium was the most effective stimulator, followed by lead, copper, silver, cobalt and other divalent cations. Calcium and magnesium had no effect.
- 英文摘要: --
- 中文關鍵字: cadmium, copper, enzyme kinetics, enzyme purification, phytochelatin synthase, Oryza sativa
- 英文關鍵字: --