AMORPHOUS [C-14]ELASTIN AS A SUBSTRATE FOR ASSAYING ELASTOLYTIC ENZYME IN CELLULAR AND TISSUE-EXTRACTS

A quantitative microassay for the detection of cellular and tissue elastolytic enzyme is presented. The enzymatic activity was detected by measuring radioactivity released from the [14C]elastin substrate. The 14C was labeled by [14C]formaldehyde on amorphous and small selected-sized elastin. The method has a high sensitivity and is capable of detecting as low as 1.2 ng of elastase. The present [14C]elastin-elastase method also proved to be a useful procedure to detect elastolytic enzyme in extracts of various tissues without purification of the enzyme or elimination of extraneous proteins. This method has been successfully employed for assaying the enzyme in tissues of lung, testis, spleen, and pancreas, as well as in peritoneal cells of rats and cells obtained from a human bronchoscopic pulmonary lavage. © 1979.