The vascular system transports components essential to the survival of the individual and acts as a barrier to substances that may injure the organism. Atherosclerosis is a dynamic, lesion producing disease of the arterial system that compromises the functioning of the organ by occlusive and thrombogenic processes. This investigation was undertaken to elucidate some of the normal biochemical processes related to the development of atherosclerosis. A significant part of the investigation was directed toward developing and combining methods and protocols to obtain the data in a concerted manner. A postmitochondnal supernatant of bovine aorta, using mevalonate-2-�����C as the substrate, was employed in the investigation. Methods included paper, thin layer, and silica gel chromatography; gel filtration, high performance liquid chromatography (HPLC), and mass spectrometry. This current research demonstrated direct incorporation of mevalonate-2- �����C into the trans-methyiglutaconic shunt intermediates. The aorta also contains alcohol dehydrogenase activity, which converts dimethylallyl alcohol and isopentenol to dimethylacrylic acid, a constituent of the trans-methylgiutaconate Small, radioactive peptides, named Nketewa as a group, were biosynthesized using mevalonate-2-�����C as the substrate. They were shown to pass through a 1000 D membrane. Acid hydrolysis and dabsyl-HPLC analysis defined the composition of the Nketewa peptides. One such peptide, Nketewa 1, had a molecular weight of 1038 and a sequence of his-gly-val-cys-phe-ala-ser-met (HGVCFASM), with a farnesyl group linked via thioether linkage to the cysteine residue. Methods were developed for the concerted investigation of the trans-methylglutaconate shunt, the isolation of mevalonate-2-�����C labeled peptides, and characteristics of neutral and acidic metabolites of mevalonate. The question as to whether or not mevalonate was the direct precursor was answered in the affirmative. These results contribute to the understanding of the biochemistry of the vessel wall and the associated atherogenic processes. Mevalonate-derived volatile and acidic compounds may represent an alternate metabolic pathway. The prenylated Nicetewa peptide may be, as are other prenylated peptides, participants in the intracellular signaling process, release of cytokines, expansion of extracellular matrix, and calcium release. / Graduation date: 2001