title: Nonaqueous capillary zone electrophoresis of synthetic organic polypeptides.
abstract: Poly(Nepsilon-trifluoroacetyl-L-lysine) was used as a model solute to investigate the potential of nonaqueous capillary electrophoresis (NACE) for the characterization of synthetic organic polymers. The information obtained by NACE was compared to that derived from size exclusion chromatography (SEC) experiments, and the two techniques were found to be complimentary for polymer characterization. On one hand, NACE permitted (i) the separation of oligomers according to their molar mass and (ii) the separation of the polymers according to the nature of the end groups. On the other hand, SEC experiments were used for the characterization of the molar mass distribution for higher molar masses. Due to the tendency of the solutes (polypeptides) to adsorb onto the fused-silica capillary wall, careful attention was paid to the rinsing procedure of the capillary between runs in order to keep the capillary surface clean. For that purpose, the use of electrophoretic desorption under denaturating conditions was very effective. Optimization of the separation was performed by studying (i) the influence of the proportion of methanol in a methanoVacetonitrile mixture and (ii) the influence of acetic acid concentration in the background electrolyte. Highly resolved separation of the oligomers (up to a degree of polymerization n of approximately 50) was obtained by adding trifluoroacetic acid to the electrolyte. Important information concerning the polymer conformations could be obtained from the mobility data. Two different plots relating the effective mobility data to the degree of polymerization were proposed for monitoring the changes in polymer conformations as a function of the number of monomers.
authors.affiliation: Laboratoire Organisation Moléculaire, Evolution et Matériaux Fluorés, UMR CNRS 5073, Université de Montpellier II, case courier 17, Place Eugène Bataillon, 34095 Montpellier Cedex 5, France. hcottet@univ-montp2.fr
authors.forename: Hervé
authors.initials: H
authors.lastname: Cottet
authors.forename: Willy
authors.initials: W
authors.lastname: Vayaboury
authors.forename: Daniel
authors.initials: D
authors.lastname: Kirby
authors.forename: Olivia
authors.initials: O
authors.lastname: Giani
authors.forename: Jacques
authors.initials: J
authors.lastname: Taillades
authors.forename: François
authors.initials: F
authors.lastname: Schué
mesh_terms: D000085:Acetates / Q000737:chemistry; D019342:Acetic Acid / Q000737:chemistry; D000097:Acetonitriles / Q000737:chemistry; D002850:Chromatography, Gel; D019075:Electrophoresis, Capillary / Q000379:methods*; D008027:Light; D008239:Lysine / Q000031:analogs & derivatives* / Q000737:chemistry; D000432:Methanol / Q000737:chemistry; D008970:Molecular Weight; D010455:Peptides / Q000032:analysis / Q000737:chemistry / Q000302:isolation & purification*; D011107:Polylysine / Q000032:analysis; D011108:Polymers / Q000032:analysis / Q000138:chemical synthesis / Q000302:isolation & purification*; D012542:Scattering, Radiation; D012997:Solvents / Q000737:chemistry
chemical_list: D000085:Acetates; D000097:Acetonitriles; C072409:N-epsilon-trifluoro-lysine; D010455:Peptides; D011108:Polymers; D012997:Solvents; D011107:Polylysine; D008239:Lysine; D019342:Acetic Acid; C018824:ammonium acetate; D000432:Methanol; C032159:acetonitrile