A single-step method for the isolation of antithrombin III

A heparin binding synthetic peptide from human HIP / RPL29 fails to specifically differentiate between anticoagulantly active and inactive species of heparin

Despite extensive progress in determining structures within heparin and heparan sulfate (Hp/HS) and the discovery of numerous proteinaceous binding partners for Hp/HS so far; the only detailed characterization of a specific protein-glycosaminoglycan interaction is antithrombin III (ATIII) binding to a Hp pentasaccharide containing a unique 3-O-sulfated glucosamine residue. Previously, it was reported from our laboratories that a 16 amino acid synthetic peptide derived from the C-terminus of human HIP/RPL29 (HIP peptide-1) enriched for ATIII-dependent anticoagulant activity, presumably by specifically binding the ATIII pentasaccharide. Herein, we demonstrate that HIP peptide-1 cannot enrich ATIII-dependent anticoagulant activity from a starting pool of porcine intestinal mucosa Hp through a bio-specific interaction. However, a HIP peptide-1 column can be used to enrich for anticoagulantly active Hp from a diverse pool of glycosaminoglycans known as Hp byproducts by a mechanism of nonspecific charge interactions. Thus, HIP peptide-1 cannot recognize Hp via bio-specific interactions but binds glycosaminoglycans by non-specific charge interactions.

Affinity chromatography in the industrial purification of plasma proteins for therapeutic use

Affinity chromatography is a powerful technique for the purification of many proteins in human plasma. Applications cover the isolation of proteins for research purposes but also, to a large extent, for the production of therapeutic products. In industrial plasma fractionation, affinity chromatography has been found to be particularly advantageous for fine and rapid capture of plasma proteins from industrial plasma fractions pre-purified by ethanol fractionation or by ion-exchange chromatography. To date, affinity chromatography is being used in the production of various licensed therapeutic plasma products, such as the concentrates of Factor VIII, Factor IX, von Willebrand Factor, Protein C, Antithrombin III, and Factor XI. Most commonly used ligands are heparin, gelatin, murine antibodies, and, to a lesser extent, Cu(2+). Possible development of the use of affinity chromatography in industrial plasma fractionation should be associated to the current development of phage display and combinatorial chemistry. Both approaches may lead to the development of tailor-made synthetic ligands that would allow implementation of protein capture technology, providing improved productivity and yield for plasma products.

Application of bioaffinity technology in therapeutic extracorporeal plasmapheresis and large-scale fractionation of human plasma

This paper describes the increasingly unique and powerful role that affinity chromatography is occupying both as a tool for the treatment of extracorporeal plasma exchange (to discard biological compounds with noxious metabolic or immunologic effects in patients) and as a purification tool in the production of therapeutic plasma protein derivatives. Management of both applications requires careful monitoring of the parameters applied to the plasma material, to avoid immunological stimulation or activation of the coagulation cascade. Examples of direct current applications of affinity ligands in therapeutic removal and industrial production of plasma compounds are presented.

Chromatography in plasma fractionation: benefits and future trends

Industrial-scale chromatographic fractionation and purification methods have been used increasingly in the last few years for plasma fractionation. This has resulted in the development of a new generation of therapeutic plasma derivatives, especially coagulation factors, protease inhibitors and anticoagulants. Implementation and combination of ion-exchange, affinity and size-exclusion chromatography have allowed the development of new therapeutic products with improved purity and safety for treating congenital or acquired plasma protein deficiencies in patients. More recently, the benefit of chromatographic purification of plasma proteins in the removal of plasma-borne viruses has been revealed. Development of packing materials with improved characteristics for industrial applications, including higher capacity and rigidity, should further promote the use of chromatography as an essential plasma fractionation tool and confine more and more the traditional ethanol precipitation methods to the final processing stages used to recover albumin.

Human plasma fractionation and the impact of new technologies on the use and quality of plasma-derived products

Recent years brought several important changes in the domain of human plasma derived products. High purity and effective anti-viral treatment became a reality. This radically improved the quality of patient treatment. At the same time recent discoveries in molecular biology paved the way for the production of several crucial plasma components by recombinant technology. In the light of these developments the future possibilities for different plasma components production is widely discussed and the eventual benefit of more expensive technologies is being evaluated. This paper, analyzes and presents methods applied by different producers to obtain plasma derived components preparations. The impact of these technologies, the quality of the products and the future of the plasma industry is being discussed.

Properties and catabolism of heat treated antithrombin III concentrate

Heat treatment is employed to diminish the transmission of hepatitis when blood products are administered. It is possible that such a procedure could reduce the biological activity of the proteins and induce changes in structure and aggregation state. We have therefore made in vitro and pharmacokinetic studies of heat treated antithrombin III (AT III) concentrate using both radiolabelled and non-labelled preparations. The purification, heat treatment and the radiolabelling procedures did not induce any changes in the AT III molecules with exception of a decrease in heparin affinity in about 10% of the molecules. The in vivo studies using 125I AT III showed that the fractional catabolic rate was increased and the half-life was shortened by about 20-25% compared to our previous studies on non-heat treated AT III concentrate. Our present findings indicating a mean half-life of 3.0 days are quite comparable to studies by others on non-heat treated AT III, however.

Pasteurisation induced changes in an antithrombin III concentrate

The changes that take place when a therapeutic antithrombin III (AT III) concentrate is heated in the presence of citrate ion have been assessed. There is some loss of heparin cofactor antithrombin activity and of heparin binding ability. Protein aggregates are also formed during heating. These aggregates are not AT III but impurities in the concentrate.