CORRELATION FREE-SOLUTION CAPILLARY ELECTROPHORESIS MIGRATION TIMES OF SMALL PEPTIDES WITH PHYSICOCHEMICAL PROPERTIES

A series of small peptides containing varying degree of charge and siz e was used to study the effects of physicochemical properties on migra tion in free-solution capillary electrophoresis (FSCE). A semiempirica l relationship between migration time under acidic conditions and the square root of molecular weight divided by the quantity of the number of the positively ionizable groups has been established. The ionizatio n of the carboxyl terminal group in the polypeptides is negligible und er acidic conditions. The relationship developed from this work has be en used for the prediction of migration parameters in free solution ca pillary electrophoresis.