Partitioning of streptokinase in aqueous two-phase systems.

The partitioning of streptokinase in aqueous two-phase systems, containing poly(ethylene glycol) and dextran or poly(ethylene glycol) and salt was investigated. The protein partitions in favour of the upper, PEG-rich phase, if PEG of low molecular weight and potassium phosphate or ammonium sulphate were used. This property was found to be independent of the degree of purity and was exploited for the partial purification of streptokinase from crude material. The protein was shown to exhibit negligible affinity to diverse triazine dyes applied in affinity partitioning experiments.