Differential binding properties of Human Pregnancy Zone Protein- and a2-Macroglobulin-proteinase complexes to low density lipoprotein receptor-related protein (LRP).

CHIABRANDO GA; VIDES MA; SÁNCHEZ MC

ARCHIVES OF BIOCHEMISTRY AND BIOPHYSICS

ELSEVIER

Año: 2002 vol. 398 p. 73 - 73

0003-9861

uman pregnancy zone protein (PZP) is a major pregnancy-associated plasma protein strongly related to alpha2-macroglobulin (alpha2-M). Both alpha-macroglobulins (alpha-Ms) covalently bind proteinases, which is accompanied by the exposure of carboxy terminal receptor recognition domains important for the rapid clearance from the circulation and tissues. It is accepted that the molecule responsible for the clearance of alpha2-M- and PZP-proteinase complexes is the low-density lipoprotein receptor-related protein (LRP). Although both alpha-M-proteinase complexes bind to the same receptor, differences in the binding properties have been reported. In addition, although it is known that the binding of alpha2-M-proteinase complexes to LRP can be blocked by Ni2+, the effect on PZP-proteinase has never been examined. In order to investigate differences in the binding properties of both alpha-Ms to the receptor, we purified LRP from human placenta by affinity chromatography and then analyzed the