Isolation and characterization of heparin from tuna skins

This study characterized heparin isolated from tuna skins. Glycosaminoglycans were isolated from tuna skin after digestion using anion exchange resin. Heparin was eluted from the resin by sodium chloride gradient and was further fractionated by acetone fractionation. Anticoagulant activity was determined using the activated partial thromboplastin time and Heptest assays. Potency was determined using amidolytic antifactor IIa and antifactor Xa assays. The presence of heparin in the extracted tuna skin glycosaminoglycans was confirmed using (13)C-nuclear magnetic resonance. The activated partial thromboplastin time and Heptest clotting times were doubled at concentrations of about 4 and 1 microg/mL, respectively. The clotting time prolongation and antiprotease activity induced by tuna heparin was readily neutralized by 25 microg/mL protamine sulfate. These results demonstrate that biologically active heparin with properties similar to clinical grade heparin can be derived from tuna skin, a raw material with otherwise relatively little economic value.