Journal of Lipid Research, Vol 32, 1403-1408, Copyright © 1991 by Lipid Research, Inc.
Isolation and characterization of calmodulin-inactivating cholesterol hydroperoxides
CL Tipton, M Shih and WJ Magat
Department of Biochemistry and Biophysics, Iowa State University, Ames 50011.
A series of cholesterol hydroperoxides has been prepared and tested as
inactivators of calmodulin. Two previously undescribed compounds,
tentatively identified as 20-(R)-25-dihydroperoxy-5-cholesten-3 beta-ol and
its 20-(S) isomer inactivate calmodulin with 50% loss of activity at 5-10
microM. Cholesterol derivatives with a single hydroperoxy group at C-20 or
C-25 are less effective, while 7 alpha-hydroperoxy- cholesterol and
25-hydroxy-cholesterol are inactive. The side-chain hydroperoxide compounds
were isolated from a mixture shown earlier to suppress formation of fatty
streaks in aortas of rabbits fed a diet supplemented with cholesterol.