title: Design of a hyperstable protein by rational consideration of unfolded state interactions.
abstract: 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.
authors.affiliation: Department of Chemistry, State University of New York at Stony Brook, Stony Brook, New York 11794-3400, USA.
authors.forename: Burcu
authors.initials: B
authors.lastname: Anil
authors.forename: Rebecca
authors.initials: R
authors.lastname: Craig-Schapiro
authors.forename: Daniel P
authors.initials: DP
authors.lastname: Raleigh
mesh_terms: 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
chemical_list: D012269:Ribosomal Proteins; C049650:ribosomal protein L9; D000409:Alanine; D005998:Glycine