Vakgroep Genetica, Genetisch Institut der Universiteit, Kruislaan 318, NL-1098 SM, Amsterdam, The Netherlands.
Planta. 1985 May;164(1):89-95. doi: 10.1007/BF00391030.
The cellular location of three peroxidase isoenzymes (PRX) in mature leaf tissue of Petunia and their affinity for Concanavalin A-Sepharose were investigated. The isoenzymes PRXa, PRXb and PRXc were identified by their positions in starch-gel zymograms. The fast-moving anodic and cathodic peroxidase bands, the isoenzymes PRXa and PRXc respectively, were the most active peroxidases in extracellular extracts. The molecular forms of PRXa showed a tissue-specific distribution between midrib and remaining leaf tissue. An intermediate-moving anodic peroxidase band, the isoenzyme PRXb, was the most active peroxidase released after extraction of isolated mesophyll protoplasts. Small amounts of the peroxidase isoenzymes were present in cell-wall-bound fractions. Incubation of a crude protein fraction with Concanavalin A-Sepharose showed that the isoenzyme PRXb bound more firmly to Concanavalin A-Sepharose than the isoenzymes PRXa and PRXc, of which only one molecular form bound partly. The results are discussed with respect to a possible function of one of the peroxidase isoenzymes, and a possible role of oligosaccharide chains in determining the cellular location of plant peroxidases is suggested.
研究了三种过氧化物酶同工酶（PRX）在矮牵牛成熟叶片组织中的细胞定位及其与伴刀豆球蛋白 A-琼脂糖的亲和力。同工酶 PRXa、PRXb 和 PRXc 通过淀粉凝胶同工酶图谱中的位置来鉴定。快速移动的阳极和阴极过氧化物酶带，同工酶 PRXa 和 PRXc 分别是细胞外提取物中最活跃的过氧化物酶。PRXa 的分子形式在中脉和剩余叶片组织之间表现出组织特异性分布。一种中等移动的阳极过氧化物酶带，同工酶 PRXb，是从分离的叶肉原生质体提取后释放的最活跃的过氧化物酶。少量过氧化物酶同工酶存在于细胞壁结合部分。用伴刀豆球蛋白 A-琼脂糖孵育粗蛋白部分表明，同工酶 PRXb 比同工酶 PRXa 和 PRXc 更牢固地结合伴刀豆球蛋白 A-琼脂糖，其中只有一种分子形式部分结合。结果与一种过氧化物酶同工酶的可能功能以及寡糖链在确定植物过氧化物酶的细胞定位方面的可能作用进行了讨论。
