Affinity-Trap Polyacrylamide Gel Electrophoresis: A Novel Method of Capturing Specific Proteins by Electro-Transfer

摘要

A method for the affinity capture of specific proteins fromna complex mixture using a polyacrylamide gel techniquenis described. The approach is based on the orthogonalnelectro-transfer of proteins separated by ordinary poly-nacrylamide gel electrophoresis (PAGE) to a ligand-couplednpolyacrylamide gel (Li-PAG), which is placed under thenPAGE gel. Upon electro-transfer, the proteins orthogonallynmigrate from the PAGE into the Li-PAG, based on the netncharge. During migration to the Li-PAG, proteins thatnspecifically interact with a ligand can be transientlyntrapped in the Li-PAG, while those that do not interactnwith a ligand pass through it. This method permits thenseparation of the proteins that can specifically interactnwith a ligand, even when present in a complex mixture.nThe method is demonstrated by applying it to the one-nstep isolation of a trypsin inhibitor from a crude extractnof soybean flour.