Cholesteryl ester analogs inhibit cholesteryl ester but not triglyceride transfer catalyzed by the plasma cholesteryl ester-triglyceride transfer protein.

A lipid transfer protein complex (LTC), purified from human plasma by immunoaffinity chromatography, catalyzed the interlipoprotein transfer of cholesteryl esters (CE) and triglycerides (TG). The CE transfer activity of LTC was governed by the structure of the CE. Incubation of LTC with long chain CE both activated and stabilized LTC. Short chain CE also enhanced the CE and TG transfer activity of LTC during the initial time of incubation. However, LTC's incubation with short chain CE induced a subsequent and time-dependent loss of CE transfer activity without concomitant loss of TG transfer activity. The data indicate that the CE and TG transfer activity of LTC can be regulated independently.