STUDY OF THE LOSS OF STREPTOKINASE ACTIVITY DURING CROSS-FLOW MICROFILTRATION .1. IMMUNOLOGICAL APPROACH

Streptokinase (SK) recovery from streptococcal fermentation broths by cross-flow microfiltration (CFMF) was studied. A loss of activity of 1 4.4% was observed, after the initial volume was concentrated eight-fol d (VCF = 8.0), recovering 51.5% of the activity in the filtrate with 3 4.1% remaining in the retentate. Only 1% of SK activity loss could be explained by protein adsorption onto the membrane, suggesting the invo lvement of other factors. Immunologic experiments using polyclonal ant ibodies against SK have demonstrated that SK activity loss during CFMF processes could be related to the denaturation of SK, with the format ion of molecules with lower (or without) activity. Accumulation of den atured SK in the retentate suggests that denaturation could be the res ult of aggregation and/or polymerization phenomena, leading to the for mation of protein aggregates that are retained by the microfiltration membrane, thus affecting the concentration effect and the fouling phen omenon.