Department of Agricultural Chemistry, Obihiro University of Agriculture and Veterinary Medicine, Obihiro, Hokkaido 080, Japan.
Plant Physiol. 1991 Jul;96(3):881-6. doi: 10.1104/pp.96.3.881.
Acid and neutral invertases were found in the mesocarp of developing muskmelon (Cucumis melo L. cv Prince) fruit and the activities of these enzymes declined with maturation of the fruit, concomitantly with the accumulation of sucrose. Neutral invertase was only present in the soluble fraction and acid invertase was present in both the soluble and cell-wall fractions. The cell-wall fraction contained three types of acid invertase: a NaCl-released invertase; an EDTA-released invertase, and a tightly bound invertase that still remained on the cell wall after treatment with NaCl and EDTA. The soluble acid and neutral invertases could be separated from one another by chromatography on DEAE-cellulose and they exhibited clear differences in their properties, namely, in their pH optima, substrate specificity, K(m) values for sucrose, and inhibition by metal ions. The EDTA-released invertase and the soluble acid invertase were similar with regard to their chromatographic behavior on DEAE-cellulose, but the NaCl-released invertase was different because it was adsorbed to a column of CM-cellulose. The soluble acid invertase and two cell-wall bound invertases had very similar characteristics with regard to optimal pH and temperature, K(m) value for sucrose, and substrate specificity.
在发育中的香瓜（Cucumis melo L. cv Prince）果实的中果皮中发现了酸性和中性转化酶，这些酶的活性随着果实的成熟而下降，与蔗糖的积累同时发生。中性转化酶仅存在于可溶部分，而酸性转化酶存在于可溶部分和细胞壁部分。细胞壁部分包含三种类型的酸性转化酶：一种 NaCl 释放的转化酶；一种 EDTA 释放的转化酶，以及一种在经过 NaCl 和 EDTA 处理后仍留在细胞壁上的紧密结合的转化酶。可溶的酸性和中性转化酶可以通过 DEAE-纤维素层析彼此分离，它们在性质上表现出明显的差异，即最适 pH 值、底物特异性、蔗糖的 K(m) 值以及金属离子的抑制作用。EDTA 释放的转化酶和可溶性酸性转化酶在 DEAE-纤维素上的层析行为相似，但 NaCl 释放的转化酶不同，因为它被吸附到 CM-纤维素柱上。可溶性酸性转化酶和两种细胞壁结合的转化酶在最适 pH 值和温度、蔗糖的 K(m) 值以及底物特异性方面具有非常相似的特征。
