Isolation and characterization of a human plasma protein with affinity for the lysine binding sites in plasminogen. Role in the regulation of fibrinolysis and identification as histidine-rich glycoprotein.

Abstract

During chromatography of plasminogen-and fibrinogen-depleted human plasma on an insolubilized fragment of plasminogen which contains the high affinity lysine-binding site (LBS I-Sepharose), both az-antiplasmin and another protein are bound and subsequently eluted with 10 m 6-aminohexanoic acid.This other protein was purified to homogeneity by DEAE-Sephadex chromatography followed by immunoadsorption and obtained with a yield of 2.5 mg/liter of plasma.Alternatively, this protein was partially purified (-80% pure) by chromatography on CM-cellulose followed by chromatography on LBS I-Sepharose and obtained with a yield of 40 mg/liter of plasma.The purified protein was found to interact with the high affinity lysine-binding site in plasmin with an