Affordable Access

Publisher Website

Hydrophobicities of di-to pentapeptides having unionizable side chains and correlation with substituent and structural parameters

DOI: 10.1016/s0165-7208(06)80050-4
  • Chemistry


Abstract Under standardized experimental conditions, we measured the partition ratio P' in a 1-octanol/pH 7.0 aqueous phosphate buffer system of a large number of zwitterionized di- to pentapeptides composed of amino acids having unionizable side chains as an approximate “molecular” partition coefficient P. The variations in log P' value of peptides were analyzed with free-energy-related physicochemical parameters for the side chain substituents and substructures. The side chain parameters representing the intrinsic hydrophobicity, the steric effect on the relative solvation of functional groups on the backbone, a d the conformational potential index derived from the Chou-Fasman β-turn propensity parameters were shown to be significant. For polar side chains, specific indicator variables attributable to intramolecular hydrogen-bond formations and the “polar proximity effect” for augmentations of hydrophobicity observed when polar groups are crowded together were required in addition. The proline residue was shown to participate in the log P' value depending not only upon its location on the backbone but also upon the total number of residues included in peptides.

There are no comments yet on this publication. Be the first to share your thoughts.