The phosphorylation of the membranal protein of the sarcoplasmic vesicles during active calcium transport.

摘要: 1 The γ-phosphate of ATP is transfered rapidly to the membranal protein isolated sarcoplasmic vesicles as soon calcium pump activated (2 4 moles phosphate per 106 g vesicular protein). The transphosphorylation occurs only if and magnesium are present SH-groups essential for transport unimpaired. 2 If, in presence magnesium, concentration free ions solution reduced from 200 about 20 nM, phosphoprotein level declines insignificant low values. dependency formation coincides with that ATP-ADP exchange reaction, extra ATPase activity accumulation. 3 The reaction well independent inside vesicles. 4 Phosphoprotein optimally when equals just extra-splitting, accumulation. 5 The amount by addition 1 mM ADP 60%. No further decline takes place raised above mM, while increasing concentrations inhibit progressively extra-splitting transport. complex which exists disappears and/or chelated. 6 The stability has its optimum at pH 2. Neither molybdate nor mercury accelerate hydrolysis phosphoprotein, hydroxylamine catalizes decay. 7 The not affected appreciably treated hydrazine under optimal conditions phosphorylation.