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Title: Occurrence and characteristics of a rapid exchange of phosphate oxygens catalyzed by sarcoplasmic reticulum vesicles

Abstract

Sarcoplasmic reticulum vesicles prepared from rabbit skeletal muscle catalyze a rapid P/sub i/ reversible HOH exchange in the presence of Mg/sup 2 +/ and absence of ATP and Ca/sup 2 +/. The capacity for oxygen exchange is about 14 times the potential capacity for ATP cleavage in the presence of Ca/sup 2 +/. No detectable exchange is found without added MgCl/sub 2/. The exchange is unaffected by oligomycin, 2,4-dinitrophenol, or ouabain, but strongly inhibited by low concentrations of Ca/sup 2 +/ in the medium. The Ca/sup 2 +/ ion concentration giving a half-maximum inhibition is 2.0 ..mu..M in the presence of 5 mM MgCl/sub 2/. A Hill plot of the Ca/sup 2 +/ inhibition gives a straight line with a Hill coefficient of 1.8. The Ca/sup 2 +/ inhibition is competitively overcome by additional Mg/sup 2 +/. The P/sub i/ reversible HOH exchange is almost completely inhibited by the detergent Triton X-100 at low concentrations in which the ATPase activity is not disturbed. Sarcoplasmic reticulum vesicles are phosphorylated by P/sub i/ in the presence of Mg/sup 2 +/ and absence of Ca/sup 2 +/ under conditions similar to those for the P/sub i/ reversible HOH exchange. The phosphorylation requires Mg/supmore » 2 +/ and is strongly inhibited by low concentrations of Ca/sup 2 +/. The response of the phosphorylation to Ca/sup 2 +/ is quite similar to that of the P/sub i/ reversible HOH exchange; the Ca/sup 2 +/ ion concentration giving a half-maximum inhibition is 2.0 ..mu..M in the presence of 5 mM MgCl/sub 2/, and the Hill coefficient is about 2.0. The various properties of the exchange give strong support to the probability that it results from reversal of steps in the over-all process associated with Ca/sup 2 +/ transport driven by ATP cleavage.« less

Authors:
;
Publication Date:
OSTI Identifier:
7361429
Alternate Identifier(s):
OSTI ID: 7361429
Resource Type:
Journal Article
Resource Relation:
Journal Name: J. Biol. Chem.; (United States); Journal Volume: 248:9
Country of Publication:
United States
Language:
English
Subject:
59 BASIC BIOLOGICAL SCIENCES; ANTIBIOTICS; BIOLOGICAL EFFECTS; ATP; BIOCHEMICAL REACTION KINETICS; CLEAVAGE; ATP-ASE; DINITROPHENOL; MUSCLES; OUABAIN; PHOSPHATES; CALCIUM; CATALYSIS; MAGNESIUM CHLORIDES; OXYGEN; PHOSPHORYLATION; RABBITS; ALKALINE EARTH METAL COMPOUNDS; ALKALINE EARTH METALS; ANIMALS; AROMATICS; CARBOHYDRATES; CARDIOTONICS; CHEMICAL REACTIONS; CHLORIDES; CHLORINE COMPOUNDS; CRYOGENIC FLUIDS; CRYSTAL STRUCTURE; DRUGS; ELEMENTS; ENZYMES; ESTERASES; FLUIDS; GLYCOSIDES; HALIDES; HALOGEN COMPOUNDS; HYDROLASES; HYDROXY COMPOUNDS; KINETICS; MAGNESIUM COMPOUNDS; MAMMALS; METALS; MICROSTRUCTURE; NITRO COMPOUNDS; NONMETALS; NUCLEOTIDES; ORGANIC COMPOUNDS; ORGANIC NITROGEN COMPOUNDS; OXYGEN COMPOUNDS; PHENOLS; PHOSPHATASES; PHOSPHORUS COMPOUNDS; REACTION KINETICS; STEROIDS; STROPHANTIN; VERTEBRATES 550200* -- Biochemistry

Citation Formats

Kanazawa, T., and Boyer, P.D. Occurrence and characteristics of a rapid exchange of phosphate oxygens catalyzed by sarcoplasmic reticulum vesicles. United States: N. p., 1973. Web.
Kanazawa, T., & Boyer, P.D. Occurrence and characteristics of a rapid exchange of phosphate oxygens catalyzed by sarcoplasmic reticulum vesicles. United States.
Kanazawa, T., and Boyer, P.D. Thu . "Occurrence and characteristics of a rapid exchange of phosphate oxygens catalyzed by sarcoplasmic reticulum vesicles". United States. doi:.
@article{osti_7361429,
title = {Occurrence and characteristics of a rapid exchange of phosphate oxygens catalyzed by sarcoplasmic reticulum vesicles},
author = {Kanazawa, T. and Boyer, P.D.},
abstractNote = {Sarcoplasmic reticulum vesicles prepared from rabbit skeletal muscle catalyze a rapid P/sub i/ reversible HOH exchange in the presence of Mg/sup 2 +/ and absence of ATP and Ca/sup 2 +/. The capacity for oxygen exchange is about 14 times the potential capacity for ATP cleavage in the presence of Ca/sup 2 +/. No detectable exchange is found without added MgCl/sub 2/. The exchange is unaffected by oligomycin, 2,4-dinitrophenol, or ouabain, but strongly inhibited by low concentrations of Ca/sup 2 +/ in the medium. The Ca/sup 2 +/ ion concentration giving a half-maximum inhibition is 2.0 ..mu..M in the presence of 5 mM MgCl/sub 2/. A Hill plot of the Ca/sup 2 +/ inhibition gives a straight line with a Hill coefficient of 1.8. The Ca/sup 2 +/ inhibition is competitively overcome by additional Mg/sup 2 +/. The P/sub i/ reversible HOH exchange is almost completely inhibited by the detergent Triton X-100 at low concentrations in which the ATPase activity is not disturbed. Sarcoplasmic reticulum vesicles are phosphorylated by P/sub i/ in the presence of Mg/sup 2 +/ and absence of Ca/sup 2 +/ under conditions similar to those for the P/sub i/ reversible HOH exchange. The phosphorylation requires Mg/sup 2 +/ and is strongly inhibited by low concentrations of Ca/sup 2 +/. The response of the phosphorylation to Ca/sup 2 +/ is quite similar to that of the P/sub i/ reversible HOH exchange; the Ca/sup 2 +/ ion concentration giving a half-maximum inhibition is 2.0 ..mu..M in the presence of 5 mM MgCl/sub 2/, and the Hill coefficient is about 2.0. The various properties of the exchange give strong support to the probability that it results from reversal of steps in the over-all process associated with Ca/sup 2 +/ transport driven by ATP cleavage.},
doi = {},
journal = {J. Biol. Chem.; (United States)},
number = ,
volume = 248:9,
place = {United States},
year = {Thu May 10 00:00:00 EDT 1973},
month = {Thu May 10 00:00:00 EDT 1973}
}