Figure 5. Zebrafish, but not C. elegans, MTP transfers triacylglycerols.
(A) COS cells expressing human, zebrafish, Drosophila, and C. elegans MTP were hypotonically lysed, centrifuged to obtain lumenal proteins and used to measure triacylglycerol transfer activity (30 μg protein/assay for human, zebrafish, and Drosophila MTP, and 50 μg protein/assay for C. elegans) using donor and acceptor vesicles (32) as elaborated in Materials and Methods. The amounts of MTP protein present in these samples were compared by Western blotting (inset, H, human; Z, zebrafish; D, Drosophila; C, C.elegans). (B) Lumenal proteins were also used to measure triacylglycerol transfer activity in the presence of donor vesicles and human LDL (3μg protein) as described in Materials and Methods.