PURIFICATION AND CHARACTERIZATION OF ACUTE-PHASE RAT PLASMA THIOSTATIN

Thiostatin was purified from acute phase plasma of turpentine-treated rats by a novel, single-step carboxymethyl-papain Sepharose 4B column chromatographic procedure. Purified thiostatin appeared as a single ba nd in SDS-PAGE with an estimated molecular weight of 68,000. Western b lot with polyclonal rabbit anti-thiostatin IgG confirmed a homogeneous immune-reactive 68 kDa species. Specific activity, as determined by e nzyme-linked immunosorbent assay (ELISA), was 0.972 mg kininogen equiv alent per mg protein. The yield of thiostatin exceeded 60% and the pro tein was purified 10.7-fold.