Capillary electrophoresis as a modern tool for determining proteolytic activities in purified specimens and in real samples

Owing to a series of interesting advantages, capillary electrophoresis (CE) is being widely used as an analytical tool for detecting enzymatic activities. On account of their resolving power, high speed, and small amount of sample required, several assays based on CE techniques have supported and/or replaced, during the past decade, traditional spectrophotometric or HPLC methods. In particular, a series of assays of practical utility have been designed for monitoring "in vitro" and "ex vivo", the hydrolytic activity of proteinases of different origin involved in the development of human diseases. The aim of the present article is to focus the interest of the reader on some recent applications of different CE modes (capillary zone electrophoresis-CZE; micellar electrokinetic chromatography-MEKC and capillary isoelectric focusing-cIEF) in the field of proteolytic enzymes to underline the wide applicability of this methodology. The article presents examples of particular interest for which the advantages and/or limitations of CE over established assays are discussed.