Rabbit muscle D-Glyceraldehyde-3-phosphate dehydrogenase: Half-of-the-sites reactivity of the enzyme modified at arginine residues
| Autor: | R.A. Asryants, E.V. Kuzminskaya, Natalia K. Nagradova |
|---|---|
| Rok vydání: | 1992 |
| Předmět: |
Arginine
Macromolecular Substances Protein Conformation Stereochemistry Biophysics Iodoacetates Dehydrogenase Biochemistry Iodoacetamide Nitrophenols Structure-Activity Relationship chemistry.chemical_compound Apoenzymes Tetramer Animals Coenzyme binding Molecular Biology Glyceraldehyde 3-phosphate dehydrogenase chemistry.chemical_classification Binding Sites biology Chemistry Hydrolysis Muscles Glyceraldehyde-3-Phosphate Dehydrogenases Cell Biology NAD Iodoacetic Acid Kinetics Enzyme biology.protein Rabbits NAD+ kinase |
| Zdroj: | Biochemical and Biophysical Research Communications. 187:577-583 |
| ISSN: | 0006-291X |
| DOI: | 10.1016/0006-291x(92)91233-g |
| Popis: | Modification of a single arginine residue per subunit of rabbit muscle apo-D-Glyceraldehyde-3-phosphate dehydrogenase does not affect the rate of hydrolysis of p-nitrophenyl acetate catalyzed by the enzyme, but locks the tetramer in a conformation wherein only two active sites are functioning. The modified enzyme also exhibits half-of-the sites reactivity towards iodoacetate and iodoacetamide. On the other hand, its NAD(+)-binding characteristics remain unchanged. Evidence is presented supporting the view that mechanisms of half-of-the-sites reactivity and negative cooperativity in coenzyme binding are different. The results are consistent with a built-in asymmetry of the tetramer and suggest that the arginine residue (probably Arg-231) controls the conformational transition between the asymmetric and symmetric states of the tetramer. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|