HIGH-PERFORMANCE CAPILLARY ELECTROPHORETIC SEPARATION OF HUMAN SERUM-ALBUMIN USING A NEUTRAL COATED CAPILLARY

A rapid, simple and highly resolving capillary electrophoresis technique is described for the separation of sub-species of clinical grade human serum albumin (HSA) using a neutral coated capillary. As the buffer pH approached the pI of HSA (5.2), eight peaks representing HSA sub-populations were resolved. On a non-coated capillary, no such resolution was obtained and buffers several pH units away from HSA's pI were required to prevent protein adsorption to the capillary wall. Some sub-species could be identified by mass spectrometric analysis as representing intact and amino-terminally damaged HSA with and without a blocked thiol at cysteine 34.