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Separation of tryptophan‐derivative enantiomers with iron‐free human serum transferrin by capillary zone electrophoresis
Author(s) -
Kilár Ference,
Fanali Salvatore
Publication year - 1995
Publication title -
electrophoresis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.666
H-Index - 158
eISSN - 1522-2683
pISSN - 0173-0835
DOI - 10.1002/elps.11501601250
Subject(s) - enantiomer , chemistry , transferrin , isoelectric point , chromatography , capillary electrophoresis , tryptophan , ionic strength , electrophoresis , isoelectric focusing , biochemistry , stereochemistry , organic chemistry , amino acid , aqueous solution , enzyme
Enantiomers can be separated by using human serum transferrin as a chiral phase. With the help of the native protein we were able to separate enantiomers with high efficiency, using a low ionic strength 2‐( N ‐morpholino)ethanesulfonic acid (MES) buffer, pH 6, in capillary zone electrophoresis. Tryptophan methyl, ethyl and butyl ester enantiomers – moving towards the cathode at pH 6 – were resolved by passing through an iron‐free transferrin zone in coated capillaries. Since the isoelectric point of the iron‐free transferrin is a little higher than 6, the protein zone is either not moving in the experiment or is slowly moving towards the anode. Under the simplest experimental conditions the highest resolution was obtained for the butyl ester enantiomers and the lowest for the methyl ester ones. By changing the experimental conditions, however, this order could be reversed. The results indicate that the lengths of the alkyl chains in the enantiomers have a significant effect on the resolution, i.e. , on the interaction between the protein and the separands.