Dissection of the protein G B1 domain binding site for human IgG Fc fragment.

Journal Article (Journal Article)

The contribution to the free energy of binding of each of the residues forming the binding site for a human IgG Fc fragment on the surface of the B1 domain of protein G was determined by alanine-scanning mutagenesis. The interface between these two proteins is atypical in that it is smaller than usual, polar in character, and involves two well-defined "knobs-into-holes" interactions. The bulk of the free energy of binding is contributed by three central residues, which make hydrogen bonds across the interface. Of these, the most critical interaction is formed by Glu27, which acts as a charged knob on the surface of the B1 domain, inserting into a polar hole on the Fc fragment. A single alanine mutation of this residue virtually abolishes stable complex formation. Formation of a stable interface between these two proteins is therefore dominated by a small, polar "hot spot."

Full Text

Duke Authors

Cited Authors

  • Sloan, DJ; Hellinga, HW

Published Date

  • August 1999

Published In

Volume / Issue

  • 8 / 8

Start / End Page

  • 1643 - 1648

PubMed ID

  • 10452608

Pubmed Central ID

  • PMC2144421

International Standard Serial Number (ISSN)

  • 0961-8368

Digital Object Identifier (DOI)

  • 10.1110/ps.8.8.1643


  • eng

Conference Location

  • United States