Ishikawa T, Sakai K, Takeda T, Shigeoka S
Department of Food and Nutrition, Faculty of Agriculture, Kinki University, Nara, Japan.
FEBS Lett. 1995 Jun 19;367(1):28-32. doi: 10.1016/0014-5793(95)00539-l.
A cDNA clone (SAP1) encoding a peroxidase was isolated from a spinach cDNA library using monoclonal antibodies raised against Euglena ascorbate peroxidase. The deduced amino acid sequence of SAP1 had higher homology with the cytosolic ascorbate peroxidases from plant sources than with bacterial peroxidases and classical plant peroxidases. The peroxidase activity of recombinant SAP1 protein expressed in E. coli was 1.6-fold higher with ascorbate than with guaiacol, which was similar to those of endogenous cytosolic ascorbate peroxidases. Here we conclude that SAP1 belongs to a new type of ascorbate peroxidase from spinach.
利用针对眼虫抗坏血酸过氧化物酶产生的单克隆抗体，从菠菜cDNA文库中分离出一个编码过氧化物酶的cDNA克隆（SAP1）。与细菌过氧化物酶和经典植物过氧化物酶相比，SAP1推导的氨基酸序列与植物来源的胞质抗坏血酸过氧化物酶具有更高的同源性。在大肠杆菌中表达的重组SAP1蛋白，其以抗坏血酸为底物时的过氧化物酶活性比以愈创木酚为底物时高1.6倍，这与内源性胞质抗坏血酸过氧化物酶相似。在此，我们得出结论，SAP1属于菠菜中一种新型的抗坏血酸过氧化物酶。
