Production and characterization of a novel human recombinant alpha-1-antitrypsin in PER.C6 cells.

Alpha-1-antitrypsin (A1PI) is a proteinase inhibitor of the serpin superfamily and circulates in plasma at about 1-2 g/L. A1PI deficiency in humans often results in organ damage, particularly to the lungs and liver. Current augmentation therapies rely entirely on A1PI isolated from human plasma, thus prompting an evaluation of alternate sources.

Safety evaluation of a recombinant plasmin derivative lacking kringles 2-5 and rt-PA in a rat model of transient ischemic stroke.

Background: Tissue type plasminogen activator is the only approved thrombolytic agent for the treatment of ischemic stroke. However, it carries the disadvantage of a 10-fold increase in symptomatic and asymptomatic intracranial hemorrhage. A safer thrombolytic agent may improve patient prognosis and increase patient participation in thrombolytic treatment.

Intra-arterial administration of recombinant tissue-type plasminogen activator (rt-PA) causes more intracranial bleeding than does intravenous rt-PA in a transient rat middle cerebral artery occlusion model.

Background: Intra-arterial (IA) administration of rt-PA for ischemic stroke has the potential for greater thrombolytic efficacy, especially for a large thrombus in the M1 or M2 segment of the middle cerebral artery (MCA). Intracranial hemorrhage (ICH) is a concern with IA or intravenous (IV) administration especially as the therapeutic window is extended. However, because IA administration delivers a higher local concentration of agent, the incidence and severity of ICH may be greater than with similar doses IV.

Haemostatic safety of a unique recombinant plasmin molecule lacking kringles 2-5.

We previously demonstrated a significant margin of haemostatic safety for full-length plasmin in comparison with tissue plasminogen activator (t-PA). We now report studies that compare haemostatic safety of full-length plasmin with a novel recombinant plasmin derivative, (Δ K2-5) plasmin, consisting of kringle 1 linked to the serine protease domain of plasmin. Agent was administered intravenously in a randomised, blinded manner in a rabbit model of fibrinolytic haemorrhage.

Simplified recombinant plasmin: production and functional comparison of a novel thrombolytic molecule with plasma-derived plasmin.

A simplified and fully functional deletion mutant of plasminogen was created in which the middle portion of the molecule was removed, resulting in kringle 1 attachment to the serine protease domain. This recombinant plasminogen deletion mutant, Delta(K2-K5)Pg, was produced in the form of inclusion bodies at the yield of up to 200 mg/l in an Escherichia coli T7 expression system. Following protein refolding and purification on lysine-Sepharose, the conversion of the recombinant molecule Delta(K2-K5)Pg to the active enzyme mutant Delta(K2-K5)Pm by plasminogen activators was evaluated, and functional characteristics of the simplified plasmin were studied.