title: Evolutionary protein stabilization in comparison with computational design.
abstract: Two major strategies are currently used for stabilizing proteins: in vitro evolution and computational design. Here, we used gene libraries of the beta1 domain of the streptococcal protein G (Gbeta1) and Proside, an in vitro selection method, to identify stabilized variants of this protein. In the Gbeta1 libraries, the codons for the four boundary positions 16, 18, 25, and 29 were randomized. Many Gbeta1 variants with strongly increased thermal stabilities were found in 11 selections performed with five independent libraries. Previously, Mayo and co-workers used computational design to stabilize Gbeta1 by sequence optimization at the same positions. Their best variant ranked third within the panel of the selected variants. None of the ten computed sequences was found in the Proside selections, because several computed residues for positions 18 and 29 were not optimal for stability.
authors.affiliation: Laboratorium für Biochemie und Bayreuther Zentrum für Molekulare Biowissenschaften, Universität Bayreuth, D-95440 Bayreuth, Germany.
authors.forename: Michael
authors.initials: M
authors.lastname: Wunderlich
authors.forename: Andreas
authors.initials: A
authors.lastname: Martin
authors.forename: Claudia A
authors.initials: CA
authors.lastname: Staab
authors.forename: Franz X
authors.initials: FX
authors.lastname: Schmid
mesh_terms: D001426:Bacterial Proteins / Q000737:chemistry; D003062:Codon; D019295:Computational Biology / Q000379:methods*; D004247:DNA / Q000737:chemistry; D019143:Evolution, Molecular; D015723:Gene Library; D019791:Guanidine / Q000737:chemistry; D007700:Kinetics; D008958:Models, Molecular; D008968:Molecular Conformation; D011487:Protein Conformation; D011489:Protein Denaturation; D015202:Protein Engineering; D017510:Protein Folding; D017434:Protein Structure, Tertiary; D012984:Software; D013696:Temperature; D013816:Thermodynamics; D013997:Time Factors
chemical_list: D001426:Bacterial Proteins; D003062:Codon; C034284:IgG Fc-binding protein, Streptococcus; D004247:DNA; D019791:Guanidine