Detection and elimination of serum protein contaminants during the purification of human urinary kallikrein.

Abstract

Antiserum against purified human urinary kallikrein (HUK) found to be a homogeneous preparation by disc electrophoresis was produced in rabbits. This antiserum was found to react slightly with some serum protein components, such as albumin or albumin-like protein, as well as HUK. It is conceivable that some small amount of serum protein detectable only by the immunochemical method was contained in the electrophoretically homogeneous HUK. Although a trace amount of serum protein contained in the purified HUK could not be completely removed by physicochemical procedures, highly purified homogeneous HUK was successfully obtained by the application of affinity absorption treatment using anti-human whole serum. In immunodiffusion and in immunoelectrophoresis, antiserum against this preparation gave only 1 line of precipitin with the crude or the finally purified HUK and no line with human whole serum. This antiserum was immunochemically monospecific.