An improved Protein G with higher affinity for human/rabbit IgG Fc domains exploiting a computationally designed polar network.

ABSTRACT: Protein G is an IgG binding protein that has been widely exploited for biotechnological purposes. Rosetta protein modeling identified a set of favorable polar mutations in Protein G, at its binding interface with the Fc domain of Immunoglobulin G, that were predicted to increase the stability and tighten the binding relative to native Protein G, with only a minor perturbation of the binding mode seen in the crystal structure. This triple mutant was synthesized and evaluated experimentally. Relative to the native protein G, the mutant showed a 3.5-fold enhancement in display level on the surface of yeast and a 5-fold tighter molar affinity for rabbit and human IgG. We attribute the improved affinity to a network of hydrogen bonds exploiting specific polar groups on human and rabbit Fc. The

SUBMITTER: Jha RK 

PROVIDER: S-EPMC3966679 | biostudies-literature | 2014 Apr

REPOSITORIES: biostudies-literature