Isoforms of apolipoprotein C-I associated with individuals with coronary artery disease

Apolipoprotein C-I (apoC-I) is a 6.6 kDa serum protein associated with high density lipoproteins (HDL) and triglyceride-rich lipoproteins. In this study, apoC-I was examined in high density lipoprotein subfractions from individuals with and without coronary artery disease (CAD). New isoforms of apoC-I, were detected in the cohort of individuals with CAD using mass spectrometry while the expected apoC-I isoforms were absent. In addition, the apoC-I mass spectra for the CAD cohort had satellite peaks indicative of the involvement of oxidative processes. Further analysis of the mass spectra of the CAD and non-CAD cohorts suggest that the origin of these new isoforms may be due to genetic mutations that could compromise the function of apoC-I.

Research highlights
► Isoforms of apoC-I detected in HDL subfractions from individuals with coronary artery disease (CAD) that were not detected in the non-CAD cohort.
► m/z shifting of apoC-I isoform peaks observed at approximately +90 Da in all individuals with CAD.
► Further modifications observed in the apoC-I spectra of some individuals with CAD which showed doublet apoC-I peaks with mass differences indicative of oxidation.
► Findings contribute to the understanding of the unique functional properties of HDL.