Summary
Preparations were made of rabbit liver globulin by the method of Jaques for heparinase
and their effect on heparin studied. The results confirmed the observations of a progressive
loss of anticoagulant activity with globulin in 0.9% saline, of a loss of metachromatic
activity after phenol extraction and the reversal of the latter by alkali. The latter
observations were due to the solubility in phenol of heparin on combination with protein.
With suitable preparations, a decrease in anticoagulant activity without decrease
in metachromatic activity was observed, i.e. conversion of heparin to uroheparin.
Loss of heparin due to combination with protein and resulting precipitation, solubility
in phenol, etc. followed a protein pH-dissociation curve. Loss of heparin anticoagulant
activity due to heparinase was maximal at pH 5.4. No loss of heparin occurred at pH
values more acid than 5 or more alkaline than 7.