determination of synthetic polypeptide conformations and molecular geometrical parameters by nonaqueous CE - Archive ouverte HAL Accéder directement au contenu
Article Dans Une Revue Electrophoresis Année : 2007

determination of synthetic polypeptide conformations and molecular geometrical parameters by nonaqueous CE

Résumé

The aim of this work was to study changes in homopolypeptide chain conformation as a function of the number of residues by the modeling of the electrophoretic mobility. For this purpose, the frictional coefficients of poly(N-trifluoroacetyl-L-lysine) with different number of residues (up to 11) were determined from the absolute ionic mobilities and modeled by the hydrodynamic frictional coefficient of an equivalent cylinder. This approach allowed determination of geometrical parameters of the polypeptide chain in a liquid phase (nonaqueous solution of the BGE). The fact that the BGE and analyte are dissolved in mixed (methanol-ACN) organic solvent implied to take into account different effects and corrections that are generally not considered in aqueous solvent: namely, the effect of ion-pairs between constituents of the BGE for the calculation of the ionic strength, the effect of ion-pairs between the solutes and the electrolyte counterions and the correction due to the dielectric friction (Hubbard-Onsager equations). In addition, the influence of the ionic strength on the electrophoretic mobility was corrected using the Pitts equation, and the effect of lateral charges due to a slight deprotonation of the -NH- group in the lateral chain was also considered. From this modeling, molecular geometrical parameters relative to the linear and helicoïdal conformations were obtained with very good correlation coefficients. Interestingly, this work also points out that the use of ionic mobility modeling for extracting molecular geometrical parameters can also be applied to end-charged polypeptides with slightly charged lateral chains (3% of elementary charge per residue).

Domaines

Polymères

Dates et versions

hal-00192214 , version 1 (27-11-2007)

Identifiants

Citer

Raphael Plasson, Willy Vayaboury, Olivia Giani, Hervé Cottet. determination of synthetic polypeptide conformations and molecular geometrical parameters by nonaqueous CE. Electrophoresis, 2007, 28 (20), pp.3617. ⟨10.1002/elps.200700349⟩. ⟨hal-00192214⟩
223 Consultations
0 Téléchargements

Altmetric

Partager

Gmail Facebook X LinkedIn More