A procedure for human Pregnancy Zone Protein (and human alpha2-Macroglobulin) purification using Hidrophobic Interaction Chromatography on Phenyl-Sepharose CL-4B Column.

CHIABRANDO G., BONACCI G., SANCHEZ C., RAMOS A., ZALAZAR F., VIDES MA.

PROTEIN EXPRESSION AND PURIFICATION

ACADEMIC PRESS INC ELSEVIER SCIENCE

Año: 1997 vol. 9 p. 399 - 406

1046-5928

Abstract In the present work we describe a procedure for the purification of human pregnancy zone protein (PZP) from pooled late pregnancy plasma by using hydrophobic interaction chromatography (HIC) on a phenyl-Sepharose column. The HIC step allowed the complete isolation of haptoglobins and the partial separation of human alpha 2-macroglobulin (alpha 2-M) from a protein fraction containing PZP previously obtained by a DEAE-Sephacel chromatography. Pure and native PZP, with a recovery of nearly 25% and biological activity of protease-binding, was obtained by two definitive final steps consisting of zinc-chelate and size-filtration chromatographies. Moreover, we further present an alternative procedure for the purification of alpha 2-M from the same pregnancy plasma, based on the differential elution of PZP and alpha 2-M from the HIC. This purification step gave rise to a highly purified product with a recovery of 10%. This differential elution could be explained by differences in surface hydrophobicity observed between both proteins. In addition, considering the different hydrophobic properties exhibited by native PZP and PZP-protease complexes, HIC on phenyl-Sepharose column could also be used for separating both conformational states of PZP.