Chemistry: natural resins or derivatives; peptides or proteins; – Proteins – i.e. – more than 100 amino acid residues – Blood proteins or globulins – e.g. – proteoglycans – platelet...
Reexamination Certificate
2001-05-07
2002-05-28
Naff, David M. (Department: 1651)
Chemistry: natural resins or derivatives; peptides or proteins;
Proteins, i.e., more than 100 amino acid residues
Blood proteins or globulins, e.g., proteoglycans, platelet...
C435S214000, C424S094640, C530S412000, C530S413000
Reexamination Certificate
active
06395881
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to the field of protein purification. In particular, the subject of the present application is a process for a baseline separation of the antithrombin III variants &agr; and &bgr;.
2. Description of Related Art
One of the most challenging analytical tasks in modern bioanalysis is still the separation and characterization of proteins and peptides. The difficulties mainly derive from the complex structure of proteins, requiring several analytical techniques to get sufficient information. Conventionally used methods for protein separation are SDS-PAGE, SEC, MS, RP-HPLC etc. (ref. 1).
Although several modes of high performance liquid chromatography are well established, capillary electrophoresis (CE) and its different modes, namely capillary zone electrophoresis (CZE), SDS molecular weight capillary electrophoresis, capillary isolectric focusing (CIEF), capillary gel electrophoresis (CGE), and last, but not least, micellar electrokinetic chromatography (MEKC) are rapidly gaining in acceptance (2).
Concerning the plasma glycoprotein antithrombin III (AT-III) which is responsible for thrombin inhibition in the blood coagulation cascade, a special analytical problem lies in the fact that it consists of two variants—the &agr;- and the &bgr;-form—which are different in their affinity to the polysaccharide heparin. The availability of a reliable method to quantify AT-III&agr; and &bgr; in, for example, plasma-derived concentrates and body fluids, will help to elucidate the currently not fully understood existence of the two isoforms.
In order to define the quality of AT-III, it is therefore meaningful to characterize it by the measurement of its portions of the &agr;- and &bgr;-variants and to develop methods for their separation.
REFERENCES:
patent: WO96/22524 (1996-07-01), None
patent: WO97/04308 (1997-02-01), None
patent: WO97/11363 (1997-03-01), None
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Doenges Reiner
Roemisch Juergen
Stauss Harald
Aventis Behring GmbH
Meller Mike
Naff David M.
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