Isolation of lectin from lamprey serum

A 105-kDa polymer lectin was purified from lamprey (Lampetra japonica) serum. The purification protocol involved ion exchange chromatography with SP-Sepharose and size exclusion chromatography on Superdex 200. The lectin was adsorbed on SP-Sepharose columns. Finally, the lectin gave an absorbance peak which corresponded to 105 kDa based on results of size exclusion chromatography. Native-PAGE and SDS-PAGE respectively displayed a single band at around 105 kDa and 35 kDa, indicating that the protein exists as a trimer. This protein, after Native-PAGE and SDS-PAGE, was excised from the gel and further analysis by MALDI-TOF/TOF as serum lectin (gi: 13094239). The lectin was able to agglutinate rabbit red blood cells (RRBCs) and sheep red blood cells (SRBCs) in vitro. In this study, we isolated lectin from lamprey serum which might be helpful to deeply research the Variable Lymphocyte Receptors mediate innate immune molecules dependent immune defence in jawless vertebrates.