FIGURE 7.

Angptl4 promotes conversion of LPL to forms with lower heparin affinity, and this is promoted in the presence of apolipoprotein-containing emulsion particles. A, ¹²⁵I-labeled LPL (∼6 nm) was subjected to different conditions and was then applied to a heparin-Sepharose column and eluted by a gradient of NaCl to separate different molecular forms of the enzyme. LPL was applied directly on the column without any pretreatment (■), preincubated for 15 min at 42 °C (▴), or preincubated at room temperature for 15 min with 73 nm angptl4 (○). B, LPL was preincubated for 15 min in room temperature in the absence (▾) or presence of emulsion particles isolated from Intralipid with 2 μm apoC-I (□) or with 2 μm apoC-I and 73 nm angptl4 (▵). C, same as panel B but with apoC-III instead of apoC-I.