Design of a hyperstable protein by rational consideration of unfolded state interactions.
Stabilization of proteins is a long-sought objective. Targeting the unfolded state interactions of a protein is not a method used for this purpose, although many proteins are known to contain such interactions. The N-terminal domain of ribosomal protein L9 (NTL9) has a lysine residue at position 12, which makes strong non-native interactions in the unfolded state. Substitution of a d-alanine for G34 in NTL9 is known to stabilize the protein by reducing the entropy of the unfolded state. Here we combine these two mutations to design a hyperstable protein. The structure of the variant is the same as that of wild-type as judged by 2D NMR. The variant is hyperstable as judged by denaturation experiments, where complete thermal unfolding of the protein does not occur in native buffer.
Anil
Burcu
B
Department of Chemistry, State University of New York at Stony Brook, Stony Brook, New York 11794-3400, USA.
Craig-Schapiro
Rebecca
R
Raleigh
Daniel P
DP
D000409:Alanine / Q000737:chemistry; D019943:Amino Acid Substitution; D002942:Circular Dichroism; D005998:Glycine / Q000737:chemistry; D008958:Models, Molecular; D016297:Mutagenesis, Site-Directed; D017510:Protein Folding; D020836:Protein Structure, Quaternary; D017433:Protein Structure, Secondary; D012269:Ribosomal Proteins / Q000737:chemistry*; D013329:Structure-Activity Relationship
D012269:Ribosomal Proteins; C049650:ribosomal protein L9; D000409:Alanine; D005998:Glycine