Predictive model for capillary electrophoretic peptide mobility in 2,2,2-trifluoroethanol-water solution.
Using capillary electrophoresis (CE) on a set of 21 peptides with a molecular mass ranging from about 350 to 1850 Da, the Stokes radii at different protonation stages and the acidic dissociation constants in water and in a 2,2,2-trifluoroethanol (TFE) water mixture (30% v/v) were determined. These results permitted us to establish separately the reliability of semiempirical models utilized for the prediction of peptide size and charge at different acidic pHapp (pHapp range: 2.00-4.25). The data obtained on size and charge were utilized in order to provide suitable mobility predictions on the basis of the charge-to-size ratio. The best predictive conditions for size and charge were found at the most acidic range of pHapp studied (2.00-2.25), either in water or a TFE-water mixture, and reliable predictive equations for peptide mobility were established at this pHapp.
Castagnola
M
M
Istituto di Chimica Biologica, Università di Cagliari, Italy. m.castagnola@uniserv.ccr.rm.cnr.it
Rossetti
D V
DV
Corda
M
M
Pellegrini
M
M
Misiti
F
F
Olianas
A
A
Giardina
B
B
Messana
I
I
D019075:Electrophoresis, Capillary / Q000379:methods; D008432:Mathematical Computing; D008958:Models, Molecular; D010455:Peptides / Q000032:analysis*; D012996:Solutions; D014270:Trifluoroethanol; D014867:Water
D010455:Peptides; D012996:Solutions; D014867:Water; D014270:Trifluoroethanol