ABSTRACT
Thiostatin was isolated by ammonium sulfate fractionation, followed by ion-exchange chromatography, gel filtration, affinity chromatography, and preparative electrophoresis in polyacrylamide gel. The relationship between the changes in concentration of thiostatin and those of other proteins in serum during the acute phase response can best be demonstrated by crossed immunoelectrophoresis. The purified protein was found to be homogeneous in crossed immunoelectrophoresis, immunoelectrophoresis, and double immunodiffusion, using antiserum to total acute phase serum. Inducing acute inflammation by subcutaneous injection of turpentine also leads to a change of the ratio of the intravascular pool of thiostatin to the extravascular pool of thiostatin. Thiostatin is synthesized in the liver via a precursor protein, which is posttranslationally modified into the mature protein. The circular dichroic spectrum of thiostatin was measured between 190 and 240 nm, and the content of the a-helix structure was found to be about 26.5%, calculated according to Chen and Yang.
