Partition of isomeric dipeptides in poly(ethylene glycol)/magnesium sulfate aqueous two-phase systems.
A series of isomeric dipeptides, i.e., those containing identical residues but in different order such as Trp-Gly versus Gly-Trp, was partitioned in a poly(ethylene glycol) (PEG)/magnesium sulfate (MgSO4) aqueous two-phase system. Dipeptides having a more hydrophobic character favored the upper (PEG) phase. Moreover, the partition coefficients for isomeric dipeptides are different, with the partition coefficients for dipeptides containing the more hydrophobic residue in the C-terminal position being, in general, greater than the partition coefficients for corresponding isomers which contain the more hydrophobic residue in the N-terminal position. These observations can be attributed to the different interactions that the isomers have with specific two-phase systems.
Eiteman
M A
MA
Department of Chemical Engineering, University of Virginia, Charlottesville 22903-2442.
Gainer
J L
JL
D004151:Dipeptides / Q000737:chemistry*; D007536:Isomerism; D008278:Magnesium Sulfate; D008956:Models, Chemical; D011092:Polyethylene Glycols; D012995:Solubility
D004151:Dipeptides; D011092:Polyethylene Glycols; D008278:Magnesium Sulfate