A new lectin from Crotalaria incana seeds and studies of toxicity in Artemia salina nauplii

Abstract

Lectins are proteins that recognize and bind to carbohydrates in a reversible and specific manner. In this work, a lectin from Crotalaria incana L. seeds was purified by Sephadex G-50 affinity chromatography. The purified lectin was named CiL and presented affinity towards D-mannose, D-glucose, D-galactose, α-methyl-D-mannoside and derivatives. CiL was stable over a wide range of temperatures and pH values, and it was divalent cation-dependent. SDS-PAGE analysis indicated that CiL is composed of two subunits with apparent masses of 29 and 30 kDa. The amino acid sequence of five tryptic peptides was obtained through mass spectrometry. Partial primary structure data indicated the similarity between CiL and lectins from Phaseolus vulgaris, Cladrastis kentukea, Lens culinaris, Pisum sativum, Crotalaria pallida and C. juncea. CiL showed no toxicity to Artemia salina nauplii at the concentration of 2 mg/mL, thus reinforcing the potential of this protein for further studies in other biological models and elucidation of possible effects.