Fig. 2.

MS detection of 3-chlorotyrosine in HDL isolated from atherosclerotic human tissue harvested at surgery. Atherosclerotic tissue was obtained from subjects undergoing carotid endarterectomy. HDL was isolated from the supernatant of tissue powder by sequential ultracentrifugation. ¹³C-Labeled internal standards were added, and the protein was hydrolyzed with acid. (A) Western blot analysis of circulating HDL (1) and lesion HDL (2) with an Ab monospecific for apoA-I. Arrow, monomeric apoA-I. (B) Analysis of derivatized amino acids derived from HDL by isotope dilution negative-ion electron capture GC/MS with selected ion monitoring.