Fractionation of heparin by chromatography on a tissue plasminogen activator-Sepharose column.
Heparin stimulates the activity of tissue plasminogen activator (t-PA) and binds to t-PA. To study this interaction, a complex between t-PA and N-acetylated heparin was formed and then linked to Sepharose. This procedure selectively links the t-PA to the column because the acetylated heparin has no free amino groups. The procedure also protects the heparin-binding site(s) on the enzyme during coupling to the matrix. The t-PA column separates heparin into two fractions, one with low affinity for t-PA and one with high affinity. Both fractions of heparin effectively accelerate inactivation of thrombin by antithrombin III. However, the fractions differ in their ability to stimulate t-PA: the low-affinity heparin has no effect on the activity of t-PA, whereas the high-affinity heparin enhances this activity. These heparin fractions will be useful in characterizing the biochemical basis and physiological consequences of the heparin--t-PA interaction.
Andrade-Gordon
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P
Department of Molecular Pharmacology, State University of New York, Stony Brook 11794-8651.
Strickland
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S
D000805:Angiotensin III / Q000494:pharmacology; D000818:Animals; D002846:Chromatography, Affinity / Q000379:methods; D002850:Chromatography, Gel; D006493:Heparin / Q000302:isolation & purification* / Q000378:metabolism / Q000494:pharmacology; D007413:Intestinal Mucosa; D007700:Kinetics; D011485:Protein Binding; D012685:Sepharose; D013552:Swine; D013917:Thrombin / Q000378:metabolism; D010959:Tissue Plasminogen Activator / Q000378:metabolism
D000805:Angiotensin III; D006493:Heparin; D012685:Sepharose; D013917:Thrombin; D010959:Tissue Plasminogen Activator