Arginyl residue modification of the sarcoplasmic reticulum ATPase protein
| Autor: | Alexander J. Murphy |
|---|---|
| Rok vydání: | 1976 |
| Předmět: |
Biophysics
Diacetyl Arginine Biochemistry chemistry.chemical_compound Residue (chemistry) Reaction rate constant Animals Magnesium Molecular Biology Adenosine Triphosphatases Binding Sites Muscles Endoplasmic reticulum Vesicle Cell Biology Phosphate Butanones MOPS Enzyme Activation Kinetics Sarcoplasmic Reticulum EGTA chemistry Reagent Calcium Rabbits Protein Binding |
| Zdroj: | Biochemical and Biophysical Research Communications. 70:1048-1054 |
| ISSN: | 0006-291X |
| DOI: | 10.1016/0006-291x(76)91008-1 |
| Popis: | Reaction of rabbit sarcoplasmic reticulum vesicles with the arginyl residue reagent 2,3-butanedione results in the inactivation of the Ca+2-dependent ATPase activity. At pH 6.9, 25°, with 10 mM butanedione the pseudo-first order rate constant is 0.075 min−1. The kinetics approach zero order at 100 mM butanedione, suggesting that reversible binding of the reagent precedes the inactivation reaction. The presence of Mg-ATP strongly protects against inactivation. Similar but less effective protection is displayed by Mg-ADP and Ca-ATP, while Ca-acetyl phosphate or Mg+2 plus AMP or tripolyphosphate are ineffective. Measurement of the binding of [14C] ATP indicates that butanedione modification results in the complete loss of affinity for the substrate. These results suggest that one or more arginyl residues play a role in the substrate-active site interaction. |
| Databáze: | OpenAIRE |
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