Preparative Electro-phoresis: An Improved Method for the Isolation of Human Recombinant Apolipoprotein A-I

摘要

Protein expression is a powerful technique to study the functional role of proteins both in vivo and in vitro. Various systems have been established to produce proteins in milligram quantities; however, the purification of many expressed proteins commonly results in trace amounts. We report on an improved method for the isolation of apolipoprotein A-I (apoA-I) using the Model 491 Prep Cell (Bio-Rad, Munich, Germany). This system has been previously used for similar protein isolation problems (3,7). We expressed apoA-I using a baculovirus system in Chinese hamster ovary (CHO) cells and in E. coli in excess (8), Apolipoproteins such as apoA-I are amphiphilic, and their purification is known to be difficult because of their amphipathic properties. Several purification methods have been used for isolating apoA-I (1,2,8,9); however, none of these isolation procedures has succeeded in separating proteins with the difference of 2 kDa in their molecular weight. Our method combines the advantages of easy handling, high efficacy and rapid purification.