1.14.15.6 Ca2+ increased rate of association of cholesterol to partially purified cytochrome P-450scc 285417 1.14.15.6 Ca2+ ineffective activator 285414 1.14.15.6 Ca2+ particulary but also other metal ions modulate adrenodoxin binding to adrenodoxin reductase and P-450, therefore activation of cholesterol side chain cleavage and adrenodoxin reduction 285414 1.14.15.6 Ca2+ very little 285413 1.14.15.6 Fe2+ a cytochrome P450 enzyme 687970 1.14.15.6 Fe2+ cytochrome P450 enzyme 688147 1.14.15.6 Fe2+ heme iron 675689, 702781 1.14.15.6 Mg2+ - 285413 1.14.15.6 Mg2+ increased MgCl2 concentrations continue to increase side chain cleavage activity even after all adrenodoxin is reduced 285414 1.14.15.6 additional information increase of side chain cleavage activity from 50 to 100 mM NaCl, higher concentrations cause a decrease, total loss at 300 mM 285414 1.14.15.6 additional information Kd for adrenodoxin increases with increase of ions from NaCl, binding of adrenodoxin to P-450scc is more sensitive to changes in metal ion concentration than cholesterol binding, high salt concentrations cause fall-off in activity 285413 1.14.15.6 additional information several cations and anions promote the dissociation of adrenodoxin-cytochrome P-450scc complex, decreasing order: K+, Cs+, Rb+, Na+, Li+ and SCN-, Br-, Cl-, respectively. The order for dissotiation of adrenodoxin-adrenodoxin reductase complex: Rb+, Cs+, K+, Li+, Na+ 285421