Microsomal triglyceride transfer protein (MTP) is critical for the assembly and secretion of
apolipoprotein B (apoB) lipoproteins. Its activity is classically measured by incubating
purified MTP or cellular homogenates with donor vesicles containing radiolabeled lipids,
precipitating the donor vesicles, and measuring the radioactivity transferred to acceptor
vesicles. Here, we describe a simple, rapid, and sensitive fluorescence assay for MTP. In
this assay, purified MTP or cellular homogenates are incubated with small unilamellar donor …