Identification and characterisation of Ca2+-pectate binding peroxidases in Arabidopsis thaliana
Identification and characterisation of Ca2+-pectate binding peroxidases in Arabidopsis thaliana
复制标题
DOI：
10.1078/0176-1617-00768
复制
发表时间：
2002-11-01
影响因子：
4.3
通讯作者：
Penel, C
中科院分区：
文献类型：
--
作者：
Dunand, C;Tognolli, M;Penel, C
拟南芥基因组编码许多分泌性愈创木酚过氧化物酶（III类植物过氧化物酶，EC 1.11.1.7）。这些高等植物酶存在于液泡或质外体中，它们具有多种功能。它们在细胞壁基质内的定位对于其活性很可能很重要。在目前的工作中，使用由 Ca(2+) 交联并嵌入聚丙烯酰胺中的聚半乳糖醛酸链组成的凝胶来从拟南芥叶子中分离对 Ca(2+) 介导的果胶构象具有亲和力的蛋白质。该色谱技术选择了少量能够与Ca(2+)-果胶酸盐结合但不能与Ca(2+)-藻酸盐结合的阳离子异过氧化物酶，Ca(2+)-藻酸盐是一种类似于Ca(2+)-果胶酸盐的多糖醛酸盐凝胶。该结果表明一些拟南芥过氧化物酶在体内对果胶具有亲和力。这种特性可以使它们正确分布在细胞壁网络内。此外，11个编码拟南芥过氧化物酶的cDNA在杆状病毒-昆虫细胞系统中表达。还评估了所得重组过氧化物酶结合果胶酸钙和藻酸钙的能力。其中 3 个似乎表现出对 NaCl 作用具有抵抗力的 Ca(2+)-果胶酸盐结合活性。这些重组过氧化物酶与Ca(2+)-海藻酸盐的结合比与Ca(2+)-果胶酸盐的结合弱得多，证实了与果胶结构相互作用的特异性。
The Arabidopsis genome encodes many secretory guaiacol peroxidases (class III plant peroxidases, EC 1.11.1.7). These higher plant enzymes are found either in the vacuole or in the apoplast, where several functions have been attributed to them. Their localisation within the cell wall matrix is most likely important for their activity In the present work, a gel consisting of polygalacturonate chains cross-linked by Ca(2+) and embedded in polyacrylamide was used to separate proteins from Arabidopsis leaves having an affinity for the Ca(2+)-mediated conformation,of pectin. This chromatographic technique selected a small number of cationic isoperoxidases able to bind to Ca(2+)-pectate but not to Ca(2+)-alginate, a polyuronate gel similar to Ca(2+)-pectate. This result suggested that some of the Arabidopsis peroxidases have an affinity for pectin in vivo. Such a property could allow them to be properly distributed within the cell wall network. In addition, eleven cDNAs encoding an Arabidopsis peroxidase were expressed in the baculovirus-insect cell system. The capacity of the resulting recombinant peroxidases to bind Ca(2+)-pectate and Ca(2+)-alginate was also assessed. It appeared that 3 of them exhibited a Ca(2+)-pectate binding activity that was resistant to the action of NaCl. The binding of these recombinant peroxidases to Ca(2+)-alginate was much weaker than to Ca(2+)-pectate, confirming the specificity of the interaction with the pectic structure.