[Change in the molecular properties of sarcoplasmic reticulum Ca-ATPase during modification of the membranes with cholesterol].
The thiol reagent NBD-chloride (4-chloro-7-nitro-benzo-2-oxo-1,3-diazole) was used to determine the amount and reactivity of SH-groups of Ca-ATPase of rat skeletal muscle sarcoplasmic reticulum during hypercholesterolemia. Modification of membranes with cholesterol brought about a decrease in the total amount and reactivity of SH-groups at the cost of reduction of rapid SH-groups and decrease of the modification constant of these SH-groups. The masking effect of high concentrations of ATP on the reactivity of SH-groups in hypercholesterolemia was noticed. It is inferred that the reduced efficacy of Ca-pump work found under the same experimental conditions before is a consequence of the modification of sarcoplasmic reticulum membranes with cholesterol and change in the molecular conformation of Ca-ATPase.
D000818:Animals; D000252:Calcium-Transporting ATPases / Q000032:analysis*; D002791:Cholesterol, Dietary / Q000008:administration & dosage; D006937:Hypercholesterolemia / Q000201:enzymology*; D008297:Male; D008968:Molecular Conformation; D011817:Rabbits; D012519:Sarcoplasmic Reticulum / Q000201:enzymology*; D013438:Sulfhydryl Compounds / Q000032:analysis
D002791:Cholesterol, Dietary; D013438:Sulfhydryl Compounds; D000252:Calcium-Transporting ATPases
Izmenenie molekuliarnykh svoĭstv Ca-ATFazy sarkoplazmaticheskogo retikuluma pri modifikatsii membran kholesterinom.