Capillary electrophoretic separation of proteins and peptides by ion-pairing with heptanesulfonic acid.
Heptanesulfonic acid as ion-pairing agent was used for the separation of mixtures of low and high molecular mass peptides/proteins by capillary electrophoresis. The separation conditions used were: capillary 37 cm (30 cm to the detector) x 75 microm i.d., voltage 10 kV, phosphate buffer 50 mmol/l, ion-pairing agent heptanesulfonic acid at three different concentrations, namely, 0, 20 or 100 mmol/l, pH 2.5. The separation reflected the ion-pairing equilibria between the ion-pairing agent and the peptide/protein analytes. The influence of ion-pairing on sample mobility (running time) was more pronounced in case of the higher-molecular peptides as compared to the low molecular ones. This difference offers the possibility to separate low and high molecular peptides/proteins that under the absence of the ion-pairing agent would co-migrate. The principle of this approach was demonstrated on a randomly selected set of peptides/proteins; the practical applicability was demonstrated on a set of CNBr peptides arising from a naturally occurring mixture of collagen types I and III.
Miksík
I
I
Institute of Physiology, Academy of Sciences of the Czech Republic, Vídenská 1083, CZ-14220 Prague 4, Czech Republic. miksik@biomed.cas.cz
Charvátová
J
J
Eckhardt
A
A
Cserháti
T
T
Forgács
E
E
Deyl
Z
Z
D000818:Animals; D003094:Collagen / Q000737:chemistry; D003488:Cyanogen Bromide; D045304:Cytochromes c / Q000737:chemistry; D019075:Electrophoresis, Capillary; D006868:Hydrolysis; D007202:Indicators and Reagents; D008970:Molecular Weight; D010455:Peptides / Q000737:chemistry / Q000302:isolation & purification*; D011506:Proteins / Q000737:chemistry / Q000302:isolation & purification*; D051381:Rats; D013451:Sulfonic Acids / Q000737:chemistry*
D007202:Indicators and Reagents; D010455:Peptides; D011506:Proteins; D013451:Sulfonic Acids; D003094:Collagen; D045304:Cytochromes c; D003488:Cyanogen Bromide