MICROPREPARATIVE CAPILLARY ISOELETRIC FOCUSING OF PROTEIN AND PEPTIDE SAMPLES FOLLOWED BY PROTEIN SEQUENCING

This paper presents a simple, straightforward method for fully automated micropreparative capillary isoelectric focusing (CIEF) of protein and pep tide samples, including fully automated fraction collection from single runs followed by protein sequencing. Protein and peptide samples were separated by native CIEF. Micropreparative CIEF of proteins was carried out using capillaries with 100-mu m inner diameter; 75-mu m-i.d. capillaries were used for micropreparative CIEF of peptides. Protein and peptide components were automatically collected into vials containing carrier ampholytes and reinjected to confirm successful fraction collection. Remaining protein and peptide fractions containing carrier ampholytes were loaded directly onto the protein sequencer support without any further sample pretreatment. Protein samples were sequenced for up to 45 cycles.