Fractionation of elastase-type enzyme activity in biological fluids using a centrifugal analyser

We here describe a simple, rapid and sensitive spectrophotometric method for fractionation of elastase-type enzyme activity on a centrifugal analyser using the chromogenic substrate Suc-[Ala]3-pNA. For quantitation of metalloelastase and serine elastase, respectively, the method utilizes 20mM EDTA as ametalloenzyme inhibitor and the serine enzyme inhibitor soybean trypsin inhibitor (SBTI) in a final concentration of 2.5 g/l. Containing both serine- and metalloelastase, a pool of synovial fluids from patients with rheumatoid arthritis was used. The method is suitable for clinical studies on different body fluids or cell constituents. The investigation points out the necessity of using inhibitors when chromogenic substrates are used to measure elastase activity in biological fluids.