Identification of Banana Lectin Isoforms and Differential Acetylation Through Mass Spectrometry Approaches

Banana lectin (BanLec) exhibits specificity to glucose/mannose residues present in oligo saccharides or glycoconjugates and has attracted a lot of attention recently as a potent therapeutic agent. Structural studies and molecular cloning methods has revealed the presence of three different BanLec proteins in two species. In our study, initial mass spectrometric analysis of affinity purified native BanLec from banana pulp (Musa paradisiaca) indicated the presence of proteins with different molecular mass. Through the bottom up and top down analysis we identified three major isoforms with acetylation at N terminus. Especially, top down analysis revealed one isoform being present as non acetylated species. The combination of mass spectrometry approaches provided insights on genetic variants and differential modifications in native BanLec.