Thromb Haemost 1989; 62(02): 748-751
DOI: 10.1055/s-0038-1646895
Original Article
Schattauer GmbH Stuttgart

Stability of Plasminogen Activator Inhibitor 1 (PAI-1)

Tomas L Lindahl
The Department of Clinical Chemistry, Karolinska Hospital, Stockholm, Sweden
,
Olöf Sigurdardottir
The Department of Clinical Chemistry, Karolinska Hospital, Stockholm, Sweden
,
Björn Wiman
The Department of Clinical Chemistry, Karolinska Hospital, Stockholm, Sweden
› Author Affiliations
Further Information

Publication History

Received 30 January 1989

Accepted after revision 28 April 1989

Publication Date:
30 June 2018 (online)

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Summary

The stability of PAI-activity has been studied at different conditions. The inactivation followed first order kinetics. Lowering the temperature and decreasing the pH both, increased the stability of PAI-1 dramatically. Addition of the PAI-1 binding protein, vitronectin, to reactivated PAI-1, about doubled the halflife of PAI-1 at all conditions studied. In the presence of chloramine T, the inactivation of reactivated PAI-1 was very rapid. In this case the protective effect of purified vitronectin, human plasma or fetal calf serum, but not of bovine serum albumin, was pronounced. The stability of the spontaneously active high Mr form of PAI-1 (partially purified or in plasma), constituting a complex between PAI-1 and vitronectin, was quite similar to reactivated PAI-1 in the presence of vitronectin. Addition of pure vitronectin, human plasma or fetal calf serum to such material had no further stabilizing effect. Reactivated PAI-1, which was inactivated by incubation at physiological conditions could again be fully reactivated, in contrast to chloramine T-oxidized PAI-1, which was irreversibly inactivated.