Summary
A natural occurring heparin inhibitor was detected and was partially purified from
the mucosa of hog small intestine. The mucosa was homogenized and was extracted overnight
in 0.15 M NaCl, 0.01 M imidazole, 0.001 M EDTA, pH 6.5. When the extract was made
to 85% saturation in ammonium sulfate, a large quantity of heparin neutralizing activity
was detected in the precipitate. Each small intestine contains approximately 35,000
units of heparin neutralizing activity. This heparin inhibitor was further purified
by the procedures of zinc sulfate precipitation, ammonium sulfate fractionation, ethanol
precipitation and heparin-sepharose chromatography. A 37 fold partial purification
with 15% overall recovery was achieved to yield heparin inhibitor with specific activity
of 50-65 units per mg of protein.
