Effect of Secondary Structure on the Interactions of Peptide T4 LYS(11-36) in Mixtures of Aqueous Sodium Chloride and 2,2,2-Trifluorethanol.

Anderson, C. O. ; Spiegelberg, S. ; Prausnitz, J. M. ; Blanch, H. W.

Technical Information Center Oak Ridge Tennessee

关键词: Anisotropy;    Peptides;    Aqueous solutions;    Proteins;    Interactions;   

RP-ID  :  DE2005837230

学科分类：工程和技术（综合）

美国|英语

来源: National Technical Reports Library

【 摘 要 】

The potential of mean force for protein-protein interactions is key to the development of a statistical-mechanical model for salt-induced protein precipitation and crystallization, and for understanding certain disease states, including cataract formation and (beta)-amyloid pathology in Alzheimer's disease. Fluorescence anisotropy provides a method for quantitative characterization of intermolecular interactions due to reversible association. Monomer-dimer equilibria for the peptide T4 LYS(11-36) were studied by fluorescence anisotropy. This peptide, derived from the (beta)-sheet region of the T4 lysozyme molecule, has the potential to form amyloid fibrils. 2,2,2-trifluoroethanol (TFE) induces a change in peptide secondary structure, and was used in aqueous solutions at concentrations from 0 to 50% (v/v) at 25 and 37 C to examine the role of peptide conformation on peptide-peptide interactions. The association constant for dimerization increased with rising TFE concentration and with falling temperature. The peptide-peptide potential of mean force was computed from these association constants. Circular-dichroism measurements showed that the secondary structure of the peptide plays an important role in these strong attractive interactions due to intermolecular hydrogen-bond formation and hydrophobic interactions.