Analysis of calcitonin and its analogues by capillary zone electrophoresis and matrix-assisted laser-desorption ionization time-of-flight mass spectrometry.
Capillary zone electrophoretic (CZE) separations and mass spectrometric analysis of salmon calcitonin and related analogues were performed to generate electrophoresis and mass fingerprints for quality control of the recombinant polypeptide pharmaceutical salmon calcitonin. The calcitonins and their corresponding tryptic digests were successfully separated by CZE at low pH in fused silica capillaries dynamically modified with poly-cationic polymers. The poly-cationic modified inner surface of the fused silica capillaries generated a strong anionic electroosmotic flow (EOF). Analytes of negative, neutral, and positive charge were all swept through the capillary toward the positive electrode. Compared to Polybrene-coated capillaries, capillaries coated with PEI showed a markedly slower but much more stable electroosmotic flow. The migration order of the analytes was predicted by comparing approximate values of the charge to (molecular mass)2/3 ratios. The predicted migration order was confirmed by off-line analysis of CZE fractions with matrix-assisted laser-desorption ionization time-of-flight mass spectrometry (MALDI-TOF-MS).
Amini
Ahmad
A
Medical Products Agency, Laboratory, Box 26, Dag Hammarskjölds väg 42, 751 03 Uppsala, Sweden. Ahmad.Amini@mpa.se
Olofsson
Ing-Marie
IM
D000595:Amino Acid Sequence; D000818:Animals; D002116:Calcitonin / Q000031:analogs & derivatives* / Q000032:analysis* / Q000235:genetics; D019075:Electrophoresis, Capillary / Q000295:instrumentation / Q000379:methods*; D008969:Molecular Sequence Data; D010449:Peptide Mapping; D012474:Salmon; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / Q000295:instrumentation / Q000379:methods*
D002116:Calcitonin