Lectin pull-down assay utilizing biotin-labeled sugar chain-immobilized gold nanoparticles and streptavidin-functionalized magnetic beads.

Lectins play crucial roles in various biological processes, such as cell-cell recognition, immune responses, and pathogen infections, through the specific recognition of sugar chain structures. Therefore, elucidating lectin-sugar chain interactions is essential for understanding their physiological and pathological functions. Previously, we developed sugar chain-immobilized metal nanoparticles as tools for analyzing lectin-sugar chain interactions and isolating lectins. These nanoparticles aggregate with lectins possessing multiple subunits with sugar chain-binding sites, thereby facilitating the analysis and isolation of lectins. However, this approach is not applicable to lectins that do not induce aggregation, such as single-subunit lectins. To address this limitation, we established a lectin pull-down method employing biotin-labeled sugar chain-immobilized gold nanoparticles and streptavidin-functionalized magnetic beads. This technique enables effective analysis of sugar chain interactions involving both monomeric and multimeric lectins. The method has also been demonstrated to capture lectins from complex biological samples, such as serum and tissue homogenate. Thus, this lectin pull-down is a valuable approach for studying lectin-sugar chain interactions and offers potential for lectin isolation from biological samples.