A neutral endopeptidase in the microvillar membrane of pig intestine. Partial purification and properties.

An enzyme hydrolysing [125I]iodo-insulin B chain was enriched in preparations of intestinal microvilli. The activity could be solubilized by Triton X-100 and was partially (76-fold) purified. It was very sensitive to inhibition by phosphoramidon and was also inhibited by chelating agents. In its enzymic, molecular and immunological properties the intestinal enzyme closely resembled kidney microvillar neutral endopeptidase (kidney-brush-border neutral proteinase, EC 3.4.24.11).