Purification of human alpha 2-plasmin inhibitor using monoclonal antibody column chromatography.

alpha 2-Plasmin inhibitor (alpha 2PI) was purified directly from human plasma by using a monoclonal antibody affinity column, which recognizes the reactive site of alpha 2PI. alpha 2PI was eluted from the column under mild conditions with 50% v/v ethyleneglycol containing 0.05% Tween 80 in phosphate-buffered saline, pH 7.4. The yield was around 50% and the specific activity of the purified protein was the same as that of the best product of preparation conventionally purified alpha 2PI.