Plasma-kinin-forming enzyme in human skin: extraction and column chromatographic separation of plasma-kinin-forming enzyme and its inhibitor.

The optimal salt concentration for extraction of plasma-kinin-forming enzyme from the human skin was investigated. It was confirmed that a salt concentration higher than 1.5 M in the extraction buffer was required for optimal extraction of this enzyme. An inhibitor of this enzyme was detected in the extract with buffer alone, and the coexistence of this enzyme with the inhibitor in buffer extract was also confirmed by using G-200 gel chromatography.