Open AccessEFFECTS OF La+++, Mn++ AND RUTHENIUM RED ON Mg.Ca-ATPase ACTIVITY AND ATP-DEPENDENT Ca-BINDING OF THE SYNAPTIC PLASMA MEMBRANE
Author(s) -
Seiji Ichida,
CheHui Kuo,
Takehisa Matsuda,
Hiroshi Yoshida
Publication year - 1976
Publication title -
japanese journal of pharmacology/japanese journal of pharmacology
Language(s) - English
Resource type - Journals
eISSN - 1347-3506
pISSN - 0021-5198
DOI - 10.1254/jjp.26.39
Subject(s) - ruthenium red , chemistry , atpase , endoplasmic reticulum , membrane , calcium , biophysics , calcium atpase , enzyme , biochemistry , biology , organic chemistry
The effects of La+++, Mn++ and ruthenium red (R.R.) on Ca-uptake of synaptic plasma membranes (S.P.M.) were investigated. La+++ (0.1 mM), Mn++ (0.2 mM) and R.R. (0.1 mM) selectively inhibited Mg-Ca-ATPase but did not significantly affect Mg-ATPase activity. The apparent Ki values of La+++, Mn++ and R.R. for Mg-Ca-ATPase were 0.05, 0.06 and 0.03 mM, respectively. La+++, Mn++ and R.R. did not affect Ca-uptake at concentrations which strongly inhibited Mg-Ca-ATPase activity. These results indicate that Ca-uptake by S.P.M. differ from that by sarcoplasmic reticulum.