Purification and mass spectrometric characterization of Sesbania aculeata (Dhaincha) stem lectin.

A glucose specific lectin (STA) was isolated from Sesbania aculeata stem by using Sephadex G-50 affinity column chromatography. The lectin is a glycoprotein having 29 kDa subunit molecular weight. Two dimensional gel electrophoresis analysis revealed that the lectin existed in two isomeric forms with varied carbohydrate content as analyzed by high performance anion exchange chromatography-pulsed amperometric detector (HPAEC-PAD). Matrix-assisted laser desorption ionization-time of flight (MALDI-TOF) and N-terminal sequence (LDSLSFTYNNFE) analysis of this lectin showed 95% homology with stem lectin SL-I (accession no. AJ585523) from peanut plant. The nucleotide sequence of the lectin (STA) was submitted to the gene bank (accession no. EU263636).