PURIFICATION AND CHARACTERIZATION OF STREPTOCOCCAL PROLIFERATIVE FACTOR

[摘要] An in vivo method for the production of streptococcal proliferation factor, its purification and characterization of its physical properties were reported. Group A streptococci (Type 12, Strain NY5) were cultured in synthetic media by in vivo incubation within dialysis casing surgically implanted in rabbit peritoneum. Streptococcal exoproteins were isolated by centrifugation of the bacteria and millipore filtration. Purification of streptococcal proliferative factor was accomplished by differential solubility and molecular sieve chromatography. No proteolytic or hemolytic activity was discovered in the resulting product. The relative MW of this factor is 29,000 as determined by sodium dodecyl sulfate gels and molecular sieve chromatography. The sedimentation coefficient determined by sucrose gradient ultracentrifugation is 2.7S. Isoelectric focusing showed minimal microheterogeneity with the pI of the major band being 5.0. Thus, streptococcal proliferative factor can be produced by in vivo incubation of streptococci in synthetic media. Purification entails a rapid 2-step process. The relative MW, sedimentation coefficient and isoelectric points were established.