title: In vitro assessment of Tc-99m labeled bovine thrombin and streptokinase-activated human plasmin: concise communication.
abstract: Bovine thrombin and streptokinase-activated human plasmin have been labeled with Tc-99m using stannous reduction of pertechnetate under physiological conditions (pH 7.4). The binding efficiency of radiotechnetium to these enzymes is greater than 94%, with less than 5% of reduced but unbound Tc-99m (Sn) complex as assayed by ascending paper radiochromatography using ITLC silica gel plate. Free or unbound pertechnetate is less than 1%. In vitro enzymatic analyses of the Tc-99m-labeled enzymes demonstrate no evidence of protein denaturation or significant loss of enzymatic activity after labeling. Both labeled enzymes are biochemically active in vitro with their respective substrates.
mesh_terms: D000818:Animals; D002417:Cattle; D004789:Enzyme Activation; D005341:Fibrinolysin / Q000502:physiology*; D006801:Humans; D007553:Isotope Labeling / Q000379:methods*; D013300:Streptokinase / Q000494:pharmacology; D013667:Technetium; D013917:Thrombin / Q000502:physiology*
chemical_list: D013667:Technetium; D013300:Streptokinase; D013917:Thrombin; D005341:Fibrinolysin