Angiotensin II induces the aggregation of native and oxidized low-density lipoprotein.

Modifications of low-density lipoprotein (LDL), such as oxidation and aggregation, and angiotensin (Ang) peptides are involved in the pathogenesis of atherosclerosis. Here, we investigated the relationship between one of the Ang peptides, AngII, and two LDL modifications, oxidation and aggregation. Using polyacrylamide gel electrophoresis and aggregation assays, we noted that AngII markedly induced the aggregation of LDL and oxidized LDL (Ox-LDL), and bound to both the aggregated and non-aggregated forms.

A Fluorescence-Labeled Heptapeptide, (FITC)KP6, as an Efficient Probe for the Specific Detection of Oxidized and Minimally Modified Low-Density Lipoprotein.

Two oxidized forms of low-density lipoprotein (LDL), oxidized LDL (ox-LDL) and minimally modified LDL (MM-LDL), are believed to play a major role in the pathogenesis of atherosclerosis. Recently, we reported that a heptapeptide (Lys-Trp-Tyr-Lys-Asp-Gly-Asp, KP6) coupled through the ε-amino group of N-terminus Lys to fluorescein isothiocyanate, (FITC)KP6, bound to ox-LDL but not to LDL. In the present study, we investigated whether (FITC)KP6 could be used as a fluorescent probe for the specific detection of MM-LDL and ox-LDL.