alamethicin and Hypercholesterolemia

Using alamethicin, permitting the measurement of genuine catalytic enzyme activity, hypercholesterolemia was shown to cause a 10-30% reduction of specific Ca-ATPase activity registered at 37 degrees C and the shift of Arrhenius plot in 20-30 degrees C temperature range. Reconstruction of delipidated Ca-ATPase of sarcoplasmic reticulum membranes by egg lecithin in animals with hypercholesterolemia does not lead to the recovery of Arrhenius plot. The data obtained demonstrate that modification of temperature-dependent Ca-ATPase activity in hypercholesterolemia is associated with the changes in the polypeptide with a catalytic function and is not induced by the changes in phospholipid enzyme surroundings.

Topics: Alamethicin; Animals; Calcium-Transporting ATPases; Catalysis; Cholesterol, Dietary; Hypercholesterolemia; Male; Membrane Lipids; Rabbits; Sarcoplasmic Reticulum; Temperature