Effect of calcium-binding protein on adenosine 5'-triphosphatase activity in the brain cytosol of rats of different ages: the inhibitory role of regucalcin.
Adenosine 5'-triphosphatase (ATPase) plays a role in the process of energy conversion in the controlled hydrolysis of ATP. The effect of Ca2+ -binding protein on ATPase activity in the brain cytosol of rats of different ages was investigated. ATPase activity in the brain cytosol of 50-week-old rats was significantly decreased as compared with that of 5-week-old rats. The presence of calcium chloride (10(-5) and 10(-4) M) in the enzyme reaction mixture caused a significant increase in ATPase activity in the brain cytosol of rats of different ages. This increase was not altered by trifluoperazine (2x10(-5) M), an antagonist of calmodulin. Calmodulin (5 microg/ml), calbindin (5 microg/ml) or S-100A protein (10 microg/ml), a Ca2+ -binding protein, had no effect on ATPase activity. Meanwhile, regucalcin (10(-9) M), which is present in brain, significantly decreased ATPase activity in young and older rats. However, the effect of regucalcin was weakened by the presence of Ca2+ (10(-5) M). The addition of anti-regucalcin monoclonal antibody in the reaction mixture caused a significant elevation of ATPase activity; this increase was completely abolished by addition of regucalcin (10(-9) M). The present study suggests that regucalcin plays an inhibitory role in the regulation of ATPase activity in the brain cytosol of rats of different ages.
Hanahisa
Y
Y
Laboratory of Endocrinology and Molecular Metabolism, Graduate School of Nutritional Sciences, University of Shizuoka, Japan.
Yamaguchi
M
M
D000251:Adenosine Triphosphatases / Q000187:drug effects*; D000375:Aging / Q000378:metabolism*; D000818:Animals; D001921:Brain / Q000187:drug effects* / Q000201:enzymology / Q000648:ultrastructure; D002135:Calcium-Binding Proteins / Q000494:pharmacology* / Q000502:physiology*; D002265:Carboxylic Ester Hydrolases; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005260:Female; D047908:Intracellular Signaling Peptides and Proteins; D051381:Rats; D017208:Rats, Wistar; D015238:Sulfotransferases; D014268:Trifluoperazine / Q000494:pharmacology
D002135:Calcium-Binding Proteins; D004791:Enzyme Inhibitors; D047908:Intracellular Signaling Peptides and Proteins; D014268:Trifluoperazine; D015238:Sulfotransferases; C028152:alcohol sulfotransferase; D002265:Carboxylic Ester Hydrolases; C513325:Rgn protein, rat; D000251:Adenosine Triphosphatases