Praxedes-Garcia Priscila, Cruz-Silva Ilana, Gozzo Andrezza Justino, Abreu Nunes Viviane, Torquato Ricardo José, Tanaka Aparecida Sadae, Figueiredo-Ribeiro Rita de Cássia, Gonzalez Yamile Gonzalez, Araújo Mariana da Silva
Department of Biochemistry, Universidade Federal de São Paulo, 04044-020 São Paulo, Brazil.
ScientificWorldJournal. 2012;2012:562715. doi: 10.1100/2012/562715. Epub 2012 May 2.
Several proteins have been isolated from seeds of leguminous, but this is the first report that a protease was obtained from seeds of Caesalpinia echinata Lam., a tree belonging to the Fabaceae family. This enzyme was purified to homogeneity by hydrophobic interaction and anion exchange chromatographies and gel filtration. This 61-kDa serine protease (CeSP) hydrolyses H-D-prolyl-L-phenylalanyl-L-arginine-p-nitroanilide (K(m) 55.7 μM) in an optimum pH of 7.1, and this activity is effectively retained until 50 °C. CeSP remained stable in the presence of kosmotropic anions (PO(4) (3-), SO(4) (2-), and CH(3)COO(-)) or chaotropic cations (K(+) and Na(+)). It is strongly inhibited by TLCK, a serine protease inhibitor, but not by E-64, EDTA or pepstatin A. The characteristics of the purified enzyme allowed us to classify it as a serine protease. The role of CeSP in the seeds cannot be assigned yet but is possible to infer that it is involved in the mobilization of seed storage proteins.
已经从豆科植物种子中分离出了几种蛋白质，但这是首次报道从豆科家族的乔木巴西苏木（Caesalpinia echinata Lam.）种子中获得一种蛋白酶。通过疏水相互作用、阴离子交换色谱和凝胶过滤将该酶纯化至同质。这种61 kDa的丝氨酸蛋白酶（CeSP）在最适pH 7.1下能水解H-D-脯氨酰-L-苯丙氨酰-L-精氨酸对硝基苯胺（K(m) 55.7 μM），并且该活性在50 °C之前能有效保持。CeSP在促晶阴离子（PO(4) (3-)、SO(4) (2-)和CH(3)COO(-)）或促溶阳离子（K(+)和Na(+)）存在的情况下保持稳定。它被丝氨酸蛋白酶抑制剂TLCK强烈抑制，但不被E-64、EDTA或胃蛋白酶抑制剂A抑制。纯化酶的特性使我们将其归类为丝氨酸蛋白酶。CeSP在种子中的作用尚不能确定，但可以推断它参与种子储存蛋白的动员。
