Human recombinant lipocortin 1 (annexin 1) has anticoagulant activity on human plasma in vitro.

Lipocortin 1 is a member of a group of calcium and phospholipid binding proteins named lipocortins (Di Rosa et al. (1984) Prostglandins 28, 441-442) and also known as annexins (Crumpton (1990) Nature 345, 212). In this study we have shown that human recombinant lipocortin-1 can increase the activated partial thromboplastin time but not the prothrombin time of human plasma in vitro. This effect is dose and time dependent and is reversed by polyclonal anti-lipocortin-1 antibodies. To our knowledge, this is the first demonstration that the human recombinant protein has the same activity as the native protein on human plasma.