A Carboxylate to Amide Substitution That Switches Protein Folds |
| |
| Authors: | Prof Stefano Gianni Dr Michelle E McCully Dr Francesca Malagrinò Dr Daniela Bonetti Dr Alfonso De Simone Prof Maurizio Brunori Prof Valerie Daggett |
| |
| Institution: | 1. Istituto Pasteur—Fondazione Cenci Bolognetti and, Ist. for Mol. Biol. Pat. of CNR, Dept. Biochemical Sci., Sapienza, University of Rome, Rome, Italy;2. Department of Bioengineering, University of Washington, Seattle, WA, USA;3. Department of Biology, Santa Clara University, Santa Clara, CA, USA;4. Department of Life Sciences, Imperial College London, South Kensington, UK |
| |
| Abstract: | Metamorphic proteins are biomolecules prone to adopting alternative conformations. Because of this feature, they represent ideal systems to investigate the general rules allowing primary structure to dictate protein topology. A comparative molecular dynamics study was performed on the denatured states of two proteins, sharing nearly identical amino‐acid sequences (88 %) but different topologies, namely an all‐α‐helical bundle protein named GA88 and an α+β‐protein named GB88. The analysis allowed successful design of and experimental validation of a site‐directed mutant that promotes, at least in part, the switch in folding from GB88 to GA88. The mutated position, in which a glutamic acid was replaced by a glutamine, does not make any intramolecular interactions in the native state of GA88, such that its stabilization can be explained by considering the effects on the denatured state. The results represent a direct demonstration of the role of the denatured state in sculpting native structure. |
| |
| Keywords: | amino acids conformation analysis biophysics protein engineering protein folding |
|
|
