Comparison of different electrokinetic separation modes applicable to a model peptide mixture (collagen type I and IIICNBr fragments)

A number of electromigration separation modes were applied to the separatio n of CNBr-released peptides from rat tail tendon collagen (microemulsion el ectrokinetic chromatography, methanol- or ethanol-modified background elect rolytes and the separation in the presence of molecular sieving effect exer ting polymer, both in the presence and absence of SDS). Electrodriven separ ations with a Hypersil C-8 packed capillary were investigated as well. The best separations were obtained with either the molecular sieving effect exe rting polymer (polyethylene oxide) in the background electrolyte (whether S DS was present or absent) or with the electrodriven chromatography using th e C-8 reversed-phase packed capillary. In the latter separation system, it was possible to separate 25-27 peaks of the theoretically expected 24 pepti des in the analyzed mixture of which 17 were at least tentatively identifie d. The additional peaks apparently stem from the incomplete cleavage of the parent collagen or chains. Successful separations can be done either with predominating molecular sieving or hydrophobic partitioning mechanism. (C) 2000 Elsevier Science B.V. All rights reserved.