作者: M A Beaven , J P Moore , G A Smith , T R Hesketh , J C Metcalfe
DOI: 10.1016/S0021-9258(17)39848-4
关键词: Biochemistry 、 Pi 、 Histamine 、 Stimulation 、 Calcium 、 Phosphatidylinositol 、 Ionophore 、 Chemistry 、 Phosphorylation 、 Phosphodiesterase 、 Biophysics
摘要: Phosphatidylinositol (PI) and its phosphorylated derivatives are rapidly broken down in 2H3 cells stimulated with antigen, a time course which coincides the generation of Ca signal. Stimulated PI breakdown is absolutely dependent on Ca2+ medium concentration dependence similar to that signal histamine release described preceding paper. However, does not depend rise free cytoplasmic over range 100 nM 1 microM. Thus, stimulation by ionophore A23187 causes only small increase antigen can be selectively blocked appropriate concentrations Zn2+ (100 microM) or La3+ (10-100 have negligible effects breakdown. Both appear common external site (or sites) Km approximately equal 0.4 mM, data consistent either independent activation phosphodiesterase after antigenic stimulation, as component mechanism generated.