Isolation of alpha-1-antitrypsin from human plasma by partitioning in aqueous biphasic systems of polyethyleneglycol-phosphate

REH, GEORGINA; NERLI, BIBIANA; PICÓ, GUILLERMO

Journal of Chromatography B

Elsevier Science Ltd-

Año: 2002 vol. 780 p. 389 - 396

1570-0232

The partitioning of alpha-1-antitrypsin was assayed in biphasic aqueous systems containing potassium phosphate and two polyethyleneglycols of molecular mass 600 and 1000, respectively. In order to isolate the alpha-1-antitrypsin from serum plasma, the partitioning behaviour of human serum albumin, its principal contaminant, was also studied. Several aqueous two-phase systems with different partitioning properties were obtained by varying the PEG1000/PEG600 mass proportion.In systems with PEG1000/PEG600 mass ratio of 8, the optimal difference between the partition coefficients of both proteins was found. Under such conditions, a satisfactory purification was carried out by a three-step extraction procedure. By applying this method the alpha-1-antitrypsin specific activity increased severalfold (nearly 10 times) with a yield of 43%.