Partial purification of a 5.7K glycoprotein from bovine vitreous which inhibits both angiogenesis and collagenase activity.

An inhibitor of angiogenic activity similar to that described by Raymond and Jacobson (1) has been partially purified and shown to be a glycoprotein of molecular mass 5,700. This inhibitor gave rise to an avascular zone on the chick vitelline plexus and also negated the action of a low Mr angiogenic factor. When the angiogenic inhibitor was incubated with mammalian collagenase it inhibited the enzyme activity by nearly 70%. The relevance of these findings to the role of collagenase in angiogenesis is discussed.