A semiempirical model for the electrophoretic mobilities of peptides in free-solution capillary electrophoresis.
In this study an attempt is made to explore the effect of a peptide's size, charge, and hydrophobicity on its electrophoretic mobility (mu) as measured by free-solution capillary electrophoresis with the aim of developing a semiempirical model which incorporates these effects. The effects of peptide size (which is measured by the number of amino acids in the polypeptide chain (n] and charge on mu are independently determined by experiment in a single solvent system and combined to give the relationship (formula; see text) where the constant 5.23 X 10(-4) is postulated to depend on the solvent system used. The form of Eq. [A.1] was confirmed, and the values of the constants 5.23 X 10(-4) and 2.47 X 10(-5) were determined, by measuring the electrophoretic mobilities of 40 peptides varying in size from 3 to 39 amino acids and varying in charge from 0.33 to 14.0. Furthermore, the effect of noncharged neutral amino acids on mobility was investigated and shown to be present, but only as a minor perturbation on the effects of size and charge.
Applied Biosystems, Santa Clara, California 95050.
P D
PD
Grossman
J C
JC
Colburn
H H
HH
Lauer
D055598:Chemical Phenomena; D002627:Chemistry, Physical; D004586:Electrophoresis; D006863:Hydrogen-Ion Concentration; D008954:Models, Biological; D008970:Molecular Weight; D010455:Peptides / Q000032:analysis*
D010455:Peptides