Effect of sulfhydryl group modification on age-associated alteration of actomyosin ATPase activity in human myocardium.
Cardiac ventricular actomyosin was prepared from autopsy samples from humans ranging in age from one to 83 years, and its Ca2(+)-ATPase and K(+)-EDTA-ATPase activities were determined in the presence or absence of a sulfhydryl reagent, N-ethylmaleimide (NEM). The Ca2(+)-ATPase activity increased in the presence of appropriate concentrations of NEM. The extent of the stimulation of Ca2(+)-ATPase activity by NEM decreased significantly with age. The ratio of K(+)-EDTA-ATPase activity to Ca2(+)-ATPase activity also decreased with age. This suggests that there is an age-related modification of sulfhydryl groups in the myosin molecule.
Yoshida
K
K
Department of Legal Medicine, Osaka University Medical School, Japan.
Matoba
R
R
Fujitani
N
N
Onishi
S
S
D000251:Adenosine Triphosphatases / Q000037:antagonists & inhibitors*; D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D000252:Calcium-Transporting ATPases / Q000378:metabolism*; D002312:Cardiomyopathy, Hypertrophic / Q000473:pathology; D003327:Coronary Disease / Q000473:pathology; D004305:Dose-Response Relationship, Drug; D005033:Ethylmaleimide / Q000494:pharmacology*; D005260:Female; D006325:Heart Atria / Q000473:pathology; D006352:Heart Ventricles / Q000473:pathology; D006801:Humans; D008297:Male; D008875:Middle Aged; D009206:Myocardium / Q000473:pathology*; D009218:Myosins / Q000378:metabolism*; D013438:Sulfhydryl Compounds / Q000378:metabolism*
D013438:Sulfhydryl Compounds; D000251:Adenosine Triphosphatases; C026049:EDTA-ATPase; D009218:Myosins; D000252:Calcium-Transporting ATPases; D005033:Ethylmaleimide