Structural changes accompanying the removal of pyridoxal 5'-phosphate from phosphorylase b
| Autor: | Lillian Greer, Robert F. Steiner, Chris Gunther |
|---|---|
| Rok vydání: | 1977 |
| Předmět: |
Circular dichroism
Phosphorylases Protein Conformation Kinetics Activation energy Calorimetry Biochemistry Genetics and Molecular Biology (miscellaneous) Fluorescence chemistry.chemical_compound Structure-Activity Relationship Apoenzymes Animals Binding site Spin label Pyridoxal Protein secondary structure chemistry.chemical_classification Binding Sites Circular Dichroism Electron Spin Resonance Spectroscopy Temperature Crystallography Enzyme chemistry Spectrophotometry Pyridoxal Phosphate Spin Labels Rabbits Apoproteins Protein Binding |
| Zdroj: | Biochimica et biophysica acta. 494(1) |
| ISSN: | 0006-3002 |
| Popis: | The changes in physical properties accompanying the removal of pyridoxal 5′-phosphate from glycogen phosphorylase b have been examined. The apoenzyme retains a high degree of structural rigidity, as determined from the time decay of anisotropy. The bulk of the secondary structure remains intact, although a significant change in circular dichroism indicates some degree of alteration. The mobility of a sulfhydryl-linked spin label increases. The restoration of pyridoxal 5′-phosphate reverse this effect, with indication of interaction between subunits. One or more new binding sites for I-anilinonaphthalene-8-sulfonate appear for the apoenzyme. The kinetics of the recombination of pyridoxal 5′-phosphate with the apoenzyme, as monitored by difference spectra, indicate a high activation energy for the process. The apoenzyme is a reversibly associating system at 20–30 °C, pH 7.0. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|