Study of the Proteolytic Activity of the Tropical Legume Crotalaria spectabilis

Legumes of the genus Crotalaria contain appro ximately 550 species dispersed throughout the world, the great majority well adapted to the tropical climate. Only a limited number occurs in temperate regions. They are annual erect herbs or woody shrubs, originated from India, Africa, and Madagascar, and have been used in the paper and animal feed industry as a source of fi bers and silage, in green manure for nitrogen fi xation, particularly where control of nematodes is important, as trap plants in endemic regions of dengue, and serve as a nurse species during early reforestation, protecting against soil erosion, and as covers for control of weeds (Pacheco and Silva-López, 2010). Despite the high toxicity of seeds due to the presence of the alkaloid monocrotaline, protease inhibitors, and other compounds which are important weapons in the chemical defence of Crotalaria, there are descriptions of C. spectabilis and C. juncea being used in small communities in South America and India to treat various diseases (Maregesi et al., 2007). Plants produce a diverse array of compounds that have ecological functions and adaptive interactions, such as in defence against predators and pathogens (Croteau et al., 2000). Peptidases, also known as proteases, play crucial roles in plant defence and are commonly expressed in species of the Leguminosae family (van der Hoorn and Jones, 2004; Mosolov and Valueva, 2006). These enzymes may be classifi ed as: exopeptidases which act on the ends of protein substrates and are de signated Study of the Proteolytic Activity of the Tropical Legume Crotalaria spectabilis