Glycine to alanine substitutions in helixes of glyceraldehyde-3-phosphate dehydrogenase: effects on stability
| Autor: | Christiane Ganter, Andreas Plueckthun |
|---|---|
| Rok vydání: | 1990 |
| Předmět: |
Protein Denaturation
Circular dichroism Protein Conformation Stereochemistry Protein subunit Glycine Fluorescence spectrometry Biochemistry Protein structure Drug Stability Escherichia coli Native state Animals Glyceraldehyde 3-phosphate dehydrogenase Alanine biology Chemistry Circular Dichroism Glyceraldehyde-3-Phosphate Dehydrogenases Recombinant Proteins Kinetics Spectrometry Fluorescence biology.protein Protein stabilization Chickens |
| Zdroj: | ResearcherID |
| ISSN: | 1520-4995 0006-2960 |
| DOI: | 10.1021/bi00492a013 |
| Popis: | Glyceraldehyde-3-phosphate dehydrogenase (GAPDH) from chicken was expressed in and purified from Escherichia coli. To investigate the physical basis of possible protein stabilization strategies, the effect of substitutions of glycine residues by alanine in helical regions was determined. One Gly to Ala substitution (G316A) located in the central core of the subunit was found to strongly stabilize the protein, while the other mutations are neutral or destabilize the protein. The effect seen for the stabilizing mutant in irreversible heat denaturation correlates with the first transition in folding equilibrium experiments that is observable by fluorescence, but not with the one detected by circular dichroism measurements or in dilution-induced dissociation experiments. The stabilizing effect of a Gly to Ala substitution therefore does not seem to be caused by an entropic effect on the unfolded state. Rather, an internal cavity is filled by the substitution G316A, probably stabilizing the native state. In large oligomeric proteins, imperfect packing may be a frequent cause of limited stability. |
| Databáze: | OpenAIRE |
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