Biochemical Aspects of a Serine Protease from Caesalpinia echinata Lam. (Brazilwood)‎ Seeds : A Potential Tool to Access the Mobilization of Seed Storage Proteins

Abstract EN

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 (Km 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 (PO4 3−, SO4 2−, and CH3COO−) 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.