Abstract
1. 1. A cation-stimulated ATPase has been labelled with [32P]ATP. 2. 2. It is shown that 95% of the label passes into a phosphoprotein which has been identified by the isolation of radioactive phosphorylserine. 3. 3. Phosphorylation of the protein is stimulated by Na+ and requires the presence of Mg2+. 4. 4. K+ stimulates dephosphorylation of the phosphorylated protein, Mg2+ is required for this step also. 5. 5. Strophanthin G inhibits both the Na+- and K+-stimulated steps. The latter is more sensitive to the glycoside. 6. 6. Observed rates of phosphorylation and of dephosphorylation of the radio-active phosphoprotein are compatible with observed rates of the cation-stimulated ATPase of the same preparation.
Original language | English (US) |
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Pages (from-to) | 112-120 |
Number of pages | 9 |
Journal | BBA - General Subjects |
Volume | 104 |
Issue number | 1 |
DOIs | |
State | Published - Jun 15 1965 |