A novel vasorelaxant lectin purified from seeds of Clathrotropis nitida: partial characterization and immobilization in chitosan beads

• We present the purification of a lectin from Clathrotropis nítida (CNA).
• This is the first report of a lectin from the genus Clathrotropis.
• Characterization of CNA was discussed.
• We evaluated the vasorelaxant effect of CNA.
• The immobilization of CNA in chitosan was realized.

A novel lectin from seeds of Clathrotropis nitida (CNA) was purified and characterized. CNA is a glycoprotein containing approximately 3.3% carbohydrates in its structure. CNA promoted intense agglutination of rabbit erythrocytes, which was inhibited by galactosides and porcine stomach mucin (PSM). The lectin maintained its hemagglutinating activity after incubation in a wide range of temperatures (30–60 °C) and pH (6.0–7.0), and its binding activity was dependent on divalent cations (Ca+2 and Mg+2). SDS-PAGE showed an electrophoretic profile consisting of a single band of 28 kDa, as confirmed by electrospray ionization mass spectrometry, which indicated an average molecular mass of 27,406 ± 2 Da and the possible presence of isoforms and glycoforms. In addition, CNA exhibited no toxicity to Artemia sp. nauplii and elicited reversible and dose-dependent vasorelaxation in precontracted aortic rings. CNA was successfully immobilized on chitosan beads and was able to capture PSM in solution. This study demonstrated that CNA is a lectin that has potential as a biotechnological tool in glycomics and glycoproteomics applications.