Structural reorganization triggered by charging of Lys residues in the hydrophobic interior of a protein.

ABSTRACT: Structural consequences of ionization of residues buried in the hydrophobic interior of proteins were examined systematically in 25 proteins with internal Lys residues. Crystal structures showed that the ionizable groups are buried. NMR spectroscopy showed that in 2 of 25 cases studied, the ionization of an internal Lys unfolded the protein globally. In five cases, the internal charge triggered localized changes in structure and dynamics, and in three cases, it promoted partial or local unfolding. Remarkably, in 15 proteins, the ionization of the internal Lys had no detectable structural consequences. Highly stable proteins appear to be inherently capable of withstanding the presence of charge in their hydrophobic interior, without the need for specialized structural adaptations. The exten

SUBMITTER: Chimenti MS 

PROVIDER: S-EPMC3373022 | biostudies-literature | 2012 Jun

REPOSITORIES: biostudies-literature