Fig. 4.

Monoclonal antibodies RG3 and RE3 block LPL binding to GPIHBP1 in a cell-free LPL–GPIHBP1 binding assay. Soluble wild-type human GPIHBP1 with a carboxyl-terminal 11A12 epitope tag was incubated with 11A12-coated agarose beads and V5-tagged human LPL, in the presence or absence of mAbs RH1, RG3, RE3, RE6, RF4, or R24. After washing the beads, GPIHBP1 and any GPIHBP1-bound LPL was eluted from the beads by heating in SDS loading buffer. Shown is a Western blot on the eluted proteins with IRDye680-labeled mAb 11A12 (red) and an IRDye800-labeled V5 antibody (green).