SEPARATION OF R-HIRUDIN FROM SIMILAR SUBSTANCES BY CAPILLARY ELECTROPHORESIS

The thrombin inhibitor r-hirudin is a peptide of 65 amino acids and wi th a pi of 4.4. Capillary electrophoresis (CE) was used to separate r- hirudin from seven closely related substances which may be found as by -products or from degradation. Possibly two of these substances differ only in an isoaspartyl instead of an aspartyl binding. A baseline sep aration was possible with an acetate buffer (pH 4.4, 60 mM) containing 0.3% (m/m) PEG 20 000 and 0.1 mM Zn2+. The possibilities to prevent w all adsorption are discussed.