Interference by divalent metals in the preparation of soluble intestinal alkaline phosphatase with n-butanal

Certain factors were found to prevent quantitative recovery of soluble alkaline phosphatase from homogenates of chick duodenal mucosa during treatment with n-butanol. Divalent cations such as calcium, manganese and lead interfered when present at 0.1-0.2 mM. Magnesium and zinc were found to reduce enyme recovery when present at 1.0 mM during extraction. These metals had little effect on enzyme activity per se, whether added to the homogenates or enzyme extracts before dilution for assay. However, lead acetate may have a protective or activating effect on phosphatase, at 0.1-10 mM. Other factors affecting the recovery of enzyme activity after butanol solubilization are the state of dilution and pH of the homogenate and individual animal variation.