One-step FPLC-size-exclusion chromatography procedure for purification of rDMBT1 6 kb with increased biological activity.

Deleted in Malignant Brain Tumor 1 (DMBT1, alias SAG or gp340) is a pattern recognition receptor involved in immune defense, cell polarization, differentiation and regeneration. To investigate the role of the protein in physiological and pathological processes, the protein has often been isolated from saliva or produced in vitro and purified by a multistep affinity purification procedure using bacteria, followed by FPLC. Here, we compared a simple, one-step FPLC-SEC protocol for purification of recombinant DMBT1 6 kb, with that of the standard bacteria affinity purification-based protocol. Our data suggest that our FPLC-SEC protocol yields DMBT1 in a more native conformation.