Journal of Lipid Research, Vol. 14, 485-494, July 1973
Copyright © 1973 by Lipid Research, Inc.
Occurrence of the enzymes effecting the conversion of acetyl CoA to squalene in homogenates of hog aorta
Linda L. Slakey , Gene C. Ness , Nilofer Qureshi , and John W. Porter
Lipid Metabolism Laboratory, Veterans Administration Hospital, and the Department of Physiological Chemistry, University of Wisconsin, Madison, Wisconsin 53706
Homogenates and subcellular fractions of the intimamedia of hog aorta have been prepared and examined for the presence of the enzymes catalyzing the conversion of acetyl CoA to squalene. Enzyme activities effecting the conversion of acetyl CoA to 3-hydroxy-3-methylglutarate (HMG); HMG CoA to mevalonic acid; mevalonic acid to 5-phosphomevalonic acid, 5-pyrophosphomevalonic acid, and isopentenyl pyrophosphate; isopentenyl pyrophosphate to farnesyl pyrophosphate; and farnesyl pyrophosphate to squalene have been demonstrated in these homogenates. The overall conversion of mevalonate to squalene has also been demonstrated with recombined fractions of hog aorta homogenates. Data are also presented that suggest that phosphatases present in the crude homogenates act to cleave farnesyl pyrophosphate to farnesol, and phospho- and pyrophosphomevalonate to mevalonate.
Supplementary key words HMG CoA reductase mevalonate kinase isopentenyl pyrophosphate isomerase prenyl transferase squalene synthetase aorta cell-free systems
Submitted on November 21, 1972
Accepted on March 19, 1973