Inhibition of endothelial cell proliferation by the recombinant kringle domain of tissue-type plasminogen activator.

Tissue-type plasminogen activator (tPA) is a multidomain serine protease that converts the zymogen plasminogen to plasmin. tPA contains two kringle domains which display considerable sequence identity with those of angiostatin, an angiogenesis inhibitor. TK1-2, a recombinant kringle domain composed of t-PA kringles 1 and 2 (Ala(90)-Thr(263)), was produced by both bacterial and yeast expression systems.