Effect of tetraphenylboron on the calcium-dependent ATPase activity of sarcoplasmic reticulum.
The apparent effect of tetraphenylboron on the Ca2+-dependent ATPase activity is rather complex being dependent of the physical state of the membrane. In leaky vesicles, tetraphenylboron decreases the affinity of the enzyme for Ca2+, and high concentrations (100 microM) inhibit the enzyme. These effects are mediated by the membrane structure. In native vesicles, tetraphenylboron induces an apparent stimulation of the maximum hydrolytic activity and a decrease of the Ca2+ gradient formed due to specific Ca2+ releasing activity of the mentioned drug.
Soler
F
F
Departamento de Bioquimica y Biologia Molecular, Universidad de Murcia, Spain.
Fernandez-Belda
F
F
Gomez-Fernandez
J C
JC
D000818:Animals; D001896:Boron Compounds / Q000494:pharmacology*; D002118:Calcium / Q000378:metabolism; D000252:Calcium-Transporting ATPases / Q000378:metabolism*; D007700:Kinetics; D011817:Rabbits; D012519:Sarcoplasmic Reticulum / Q000187:drug effects / Q000201:enzymology*; D013775:Tetraphenylborate / Q000494:pharmacology*
D001896:Boron Compounds; D013775:Tetraphenylborate; D000252:Calcium-Transporting ATPases; D002118:Calcium