UC/MALDI-MS analysis of HDL; evidence for density-dependent post-translational modifications.
The purpose of this study is to determine whether the nature of the post-translational modifications of the major apolipoproteins of HDL is different for density-distinct subclasses. These subclasses were separated by ultracentrifugation using a novel density-forming solute to yield a high-resolution separation. The serum of two subjects, a control with a normolipidemic profile and a subject with diagnosed cardiovascular disease, was studied. Aliquots of three HDL subclasses were analyzed by MALDI and considerable differences were seen when comparing density-distinct subclasses and also when comparing the two subjects. A detailed analysis of the post-translational modification pattern of apoA-1 shows evidence of considerable protease activity, particularly in the more dense fractions. We conclude that part of the heterogeneity of the population of HDL particles is due to density-dependent protease activity.
Johnson
Jeffery D
JD
Department of Chemistry Texas A&M University, College Station, Texas, 77843-3255, U.S.A.
Henriquez
Ronald R
RR
Tichy
Shane E
SE
Russell
David H
DH
McNeal
Catherine J
CJ
Macfarlane
Ronald D
RD