Department of Biological Sciences, University of Illinois at Chicago, Chicago Illinois 60680.
Plant Physiol. 1991 Oct;97(2):730-5. doi: 10.1104/pp.97.2.730.
Pea (Pisum sativum L.) chloroplastic phosphoriboisomerase (EC 5.3.1.6) can be purified to apparent homogeneity in less than 2 days time with a 53% yield. Important steps in the purification include heat treatment and pseudoaffinity chromatography on Red H-3BN Sepharose. The purified isomerase has a subunit molecular mass of 26.4 kD. The N-terminal sequence has been determined through 34 residues. pH optima are 7.8 (ribose-5-phosphate) and 7.7 (ribulose-5-phosphate); K(m) values are 0.9 millimolar (ribose-5-phosphate) and 0.6 millimolar (ribulose-5-phosphate). The enzyme is inhibited by erythrose-4-phosphate, sedoheptulosebisphosphate, glyceraldehyde-3-phosphate, and 3-phosphoglycerate at concentrations close to those found in photosynthesizing chloroplasts. Countercurrent phase partitioning experiments indicate that the pea chloroplastic phosphoriboisomerase interacts physically with phosphoribulokinase.
豌豆（Pisum sativum L.）叶绿体磷酸核糖异构酶（EC 5.3.1.6）可在不到 2 天的时间内以 53%的收率被纯化至近乎均一。纯化过程中的重要步骤包括热处理和在 Red H-3BN Sepharose 上进行拟亲和层析。纯化的异构酶亚基分子量为 26.4 kD。通过 34 个残基确定了 N 端序列。最适 pH 值为 7.8（核糖-5-磷酸）和 7.7（核酮糖-5-磷酸）；K(m)值分别为 0.9 毫摩尔（核糖-5-磷酸）和 0.6 毫摩尔（核酮糖-5-磷酸）。该酶被赤藓糖-4-磷酸、景天庚酮糖-1,7-二磷酸、甘油醛-3-磷酸和 3-磷酸甘油酸抑制，其浓度接近光合作用叶绿体中的浓度。逆流分相实验表明，豌豆叶绿体磷酸核糖异构酶与磷酸核糖激酶在物理上相互作用。
