TY - JOUR
T1 - On the role of thiol groups in the inhibition of liver microsomal ca2+ sequestration by toxic agents
AU - Thor, Hjördis
AU - Hartzell, Pia
AU - Svensson, Sten Åke
AU - Orrenius, Sten
AU - Mirabelli, Francesca
AU - Marinoni, Vito
AU - Bellomo, Giorgio
N1 - Funding Information:
Acknowledgements-Thiss tudy was supportedb y grants from the SwedishM edical ResearchC ouncil, the Swedish Council for the Planninga nd Coordination of Research and the Consiglio Nazionale delle Ricerche.
PY - 1985/10/15
Y1 - 1985/10/15
N2 - ATP-dependent Ca2+ sequestration by rat liver microsomes was assayed using three different methods, and characterized with regard to the effect of various inhibitors. When glucose and hexokinase were added in combination to deplete ATP in the incubation, Ca2+ uptake was followed by rapid release of Ca2+ from the microsomes. Ca2+ sequestration was inhibited by reagents that cause alkylation (e.g. p-chloromercuribenzoate) or oxidation (e.g. diamide) of protein sulfhydryl groups. Moreover, pretreatment of the microsomes with cystamine, which causes formation of mixed disulfides with protein thiols, also resulted in the inhibition of Ca2+ sequestration. It is concluded that microsomal Ca2+ sequestration is critically dependent on protsin sulfhydryl groups, and that modification of protein thiols may be an important mechanism for the inhibition of microsomal Ca12+ sequestration by a variety of toxic agents.
AB - ATP-dependent Ca2+ sequestration by rat liver microsomes was assayed using three different methods, and characterized with regard to the effect of various inhibitors. When glucose and hexokinase were added in combination to deplete ATP in the incubation, Ca2+ uptake was followed by rapid release of Ca2+ from the microsomes. Ca2+ sequestration was inhibited by reagents that cause alkylation (e.g. p-chloromercuribenzoate) or oxidation (e.g. diamide) of protein sulfhydryl groups. Moreover, pretreatment of the microsomes with cystamine, which causes formation of mixed disulfides with protein thiols, also resulted in the inhibition of Ca2+ sequestration. It is concluded that microsomal Ca2+ sequestration is critically dependent on protsin sulfhydryl groups, and that modification of protein thiols may be an important mechanism for the inhibition of microsomal Ca12+ sequestration by a variety of toxic agents.
UR - http://www.scopus.com/inward/record.url?scp=0022217758&partnerID=8YFLogxK
U2 - 10.1016/0006-2952(85)90236-9
DO - 10.1016/0006-2952(85)90236-9
M3 - Article
SN - 0006-2952
VL - 34
SP - 3717
EP - 3723
JO - Biochemical Pharmacology
JF - Biochemical Pharmacology
IS - 20
ER -